Update bundler version for jruby app

Fixes:

```
Hatchet::App::FailedDeployError Could not deploy 'hatchet-t-741ea26fdf' (default_ruby) using 'Hatchet::GitApp' at path: './repos/rack/default_ruby'
if this was expected add `allow_failure: true` to your deploy hash.
Buildpack: nil
Repo: https://git.heroku.com/hatchet-t-741ea26fdf.git
output:
remote: Updated 5 paths from 3dac5f9        
remote: Compressing source files... done.        
remote: Building source:        
remote: 
remote: -----> Building on the Heroku-20 stack        
remote: -----> Using buildpack: https://github.com/heroku/heroku-buildpack-ruby#schneems/ci-queue-dec3        
remote: -----> Ruby app detected        
remote: 
remote:        ## Warning: Your app needs java        
remote: 
remote:        The Ruby buildpack determined your app needs java installed        
remote:        we recommend you add the jvm buildpack to your application:        
remote: 
remote:          $ heroku buildpacks:add heroku/jvm --index=1        
remote: 
remote: -----> Installing Java        
remote: 
remote: -----> Downloading Buildpack: heroku/jvm        
remote: -----> Detected Framework: JVM Common        
remote: 
remote:  !     WARNING: No OpenJDK version specified        
remote:        Your application does not explicitly specify an OpenJDK        
remote:        version. OpenJDK 1.8 will be installed.        
remote:                
remote:        This default version will change at some point. Your        
remote:        application might fail to build with the new version. We        
remote:        recommend explicitly setting the required OpenJDK version for        
remote:        your application.        
remote:                
remote:        To set the OpenJDK version, add or edit the system.properties        
remote:        file in the root directory of your application to contain:        
remote:                
remote:        java.runtime.version = 1.8        
remote:                
remote: 
remote: -----> Installing OpenJDK 1.8... done        
remote: -----> Installing bundler 1.17.3        
remote: -----> Removing BUNDLED WITH version in the Gemfile.lock        
remote: -----> Compiling Ruby/Rack        
remote: -----> Using Ruby version: ruby-2.5.7-jruby-9.2.13.0        
remote: -----> Installing dependencies using bundler 1.17.3        
remote:        Running: BUNDLE_WITHOUT='development:test' BUNDLE_PATH=vendor/bundle BUNDLE_BIN=vendor/bundle/bin BUNDLE_DEPLOYMENT=1 BUNDLE_GLOBAL_PATH_APPENDS_RUBY_SCOPE=1 bundle install -j4        
remote:        You are trying to install in deployment mode after changing        
remote:        your Gemfile. Run `bundle install` elsewhere and add the        
remote:        updated Gemfile.lock to version control.        
remote:                
remote:        If this is a development machine, remove the /tmp/build_3b0d62e8/Gemfile freeze         
remote:        by running `bundle install --no-deployment`.        
remote:                
remote:        Bundler is unlocking ruby        
remote:                
remote:        You have added to the Gemfile:        
remote:        * webrick        
remote:        Bundler Output: You are trying to install in deployment mode after changing        
remote:        your Gemfile. Run `bundle install` elsewhere and add the        
remote:        updated Gemfile.lock to version control.        
remote:                
remote:        If this is a development machine, remove the /tmp/build_3b0d62e8/Gemfile freeze         
remote:        by running `bundle install --no-deployment`.        
remote:                
remote:        Bundler is unlocking ruby        
remote:                
remote:        You have added to the Gemfile:        
remote:        * webrick        
remote:         
remote:  !        
remote:  !     Failed to install gems via Bundler.        
remote:  !        
remote:  !     Push rejected, failed to compile Ruby app.        
remote: 
remote:  !     Push failed        
remote:  !        
remote:  ! ## Warning - The same version of this code has already been built: df7a92f56ea636831f28033356791f2ba6ba0ef0        
remote:  !        
remote:  ! We have detected that you have triggered a build from source code with version df7a92f56ea636831f28033356791f2ba6ba0ef0        
remote:  ! at least twice. One common cause of this behavior is attempting to deploy code from a different branch.        
remote:  !        
remote:  ! If you are developing on a branch and deploying via git you must run:        
remote:  !        
remote:  !     git push heroku <branchname>:main        
remote:  !        
remote:  ! This article goes into details on the behavior:        
remote:  !   https://devcenter.heroku.com/articles/duplicate-build-version        
remote: 
remote: Verifying deploy...        
remote: 
remote: !	Push rejected to hatchet-t-741ea26fdf.        
remote: 
To https://git.heroku.com/hatchet-t-741ea26fdf.git
 ! [remote rejected] HEAD -> main (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/hatchet-t-741ea26fdf.git'
  /app/vendor/bundle/ruby/3.1.0/gems/heroku_hatchet-8.0.4/lib/hatchet/git_app.rb:36:in `git_push_heroku_yall'
  /app/vendor/bundle/ruby/3.1.0/gems/heroku_hatchet-8.0.4/lib/hatchet/git_app.rb:13:in `block in push_without_retry!'
  /app/vendor/bundle/ruby/3.1.0/gems/heroku_hatchet-8.0.4/lib/hatchet/shell_throttle.rb:28:in `block (2 levels) in call'
  /app/vendor/bundle/ruby/3.1.0/gems/heroku_hatchet-8.0.4/lib/hatchet/shell_throttle.rb:27:in `catch'
  /app/vendor/bundle/ruby/3.1.0/gems/heroku_hatchet-8.0.4/lib/hatchet/shell_throttle.rb:27:in `block in call'
```

https://dashboard.heroku.com/pipelines/ac057663-170b-4bdd-99d0-87560eb3a570/tests/2165

spec/hatchet/rubies_spec.rb

@@ -33,6 +33,9 @@
 
          RUBY VERSION
             ruby 2.5.7p0 (jruby 9.2.13.0)
+
+         BUNDLED WITH
+            2.5.23
         EOM
 
         Pathname("Rakefile").write(<<~'EOM')