Drop J2ObjC compiler

- build requires MacOS and external software J2ObjC
- J2ObjC support max JDK 11
- looks like not used feature
- there is replacement https://developers.google.com/j2objc/guides/maven-plugin

.github/workflows/maven.yml

@@ -30,5 +30,5 @@ jobs:
       jdk-matrix: '["11", "17", "21"]'
       jdk-distribution-matrix: '["zulu", "temurin", "microsoft", "liberica", "corretto"]'
       os-matrix: '["ubuntu-latest","windows-latest", "macOS-latest"]'
-      maven_args: 'verify javadoc:javadoc -e -B -V -fae -Pno-tests-if-not-on-osx'
+      maven_args: 'verify javadoc:javadoc -e -B -V -fae'
 

README.md

@@ -12,7 +12,3 @@ This component is an Compilation API used by Apache Maven Compiler plugin on the
 Please refer to [documentation](https://errorprone.info/docs/installation#maven) 
 
 Or the project [it test](plexus-compiler-its/src/main/it/error-prone-compiler/pom.xml)
-
-### J2ObjC OSX
-
-To compile this project on OSX, you need to have J2ObjC installed: [J2ObjC Requirements](https://developers.google.com/j2objc#requirements).