Disable CI for draft PRs (#1009)

------------------------------------------------------------------------------------------------------------

**Context:**
Tooling Team has requested that all CI checks for draft PRs across all
PennyLane repos are to be disabled to free up resources. [SC
Story](https://app.shortcut.com/xanaduai/story/66346/disable-ci-for-pl-draft-prs).

**Description of the Change:**
Conditions for checking whether a PR is in draft state have been added
to existing workflows.

**Benefits:**
Reduces resource usage.

**Possible Drawbacks:**
Some development steps are deferred to PRs in "ready for review" state
only.

**Related GitHub Issues:**
N/A

### Verification:
Created this PR as draft, no GitHub runners were used by CI. The 2
successful checks are codecov and readthedocs which do not use these
resources. When marked as "ready for review" the CI checks ran
(excluding wheel build checks). When the `author:build-wheel` label was
added, the remaining tests ran.

![Screenshot from 2024-08-09
16-46-53](https://github.com/user-attachments/assets/e66e9ca8-83c8-4a9a-a547-b1fd03c96289)

.github/workflows/build-wheel-linux-arm64.yaml

@@ -7,6 +7,7 @@ on:
       - reopened
       - synchronize
       - labeled
+      - ready_for_review
   push:
     branches: [ main ]
   workflow_dispatch:
@@ -21,6 +22,7 @@ concurrency:
 
 jobs:
   check_if_wheel_build_required:
+    if: github.event.pull_request.draft == false
     uses: ./.github/workflows/check-for-wheel-build.yml
 
   constants:

.github/workflows/build-wheel-linux-x86_64.yaml

@@ -7,6 +7,7 @@ on:
       - reopened
       - synchronize
       - labeled
+      - ready_for_review
   push:
     branches: [ main ]
   workflow_dispatch:
@@ -18,12 +19,14 @@ concurrency:
 
 jobs:
   determine_runner:
+    if: github.event.pull_request.draft == false
     name: Determine runner type to use
     uses: ./.github/workflows/determine-workflow-runner.yml
     with:
       default_runner: ubuntu-latest
 
   check_if_wheel_build_required:
+    if: github.event.pull_request.draft == false
     uses: ./.github/workflows/check-for-wheel-build.yml
 
   constants:

.github/workflows/build-wheel-macos-arm64.yaml

@@ -7,6 +7,7 @@ on:
       - reopened
       - synchronize
       - labeled
+      - ready_for_review
   push:
     branches: [ main ]
   workflow_dispatch:
@@ -21,6 +22,7 @@ concurrency:
 
 jobs:
   check_if_wheel_build_required:
+    if: github.event.pull_request.draft == false
     uses: ./.github/workflows/check-for-wheel-build.yml
 
   constants:

.github/workflows/build-wheel-macos-x86_64.yaml

@@ -7,6 +7,7 @@ on:
       - reopened
       - synchronize
       - labeled
+      - ready_for_review
   push:
     branches: [ main ]
   workflow_dispatch:
@@ -21,6 +22,7 @@ concurrency:
 
 jobs:
   check_if_wheel_build_required:
+    if: github.event.pull_request.draft == false
     uses: ./.github/workflows/check-for-wheel-build.yml
 
   constants:

.github/workflows/check-catalyst.yaml

@@ -2,6 +2,11 @@ name: Check Catalyst Build
 
 on:
   pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - ready_for_review
   push:
     branches: [ main ]
   workflow_dispatch:
@@ -12,6 +17,7 @@ concurrency:
 
 jobs:
   determine_runner:
+    if: github.event.pull_request.draft == false
     name: Determine runner type to use
     uses: ./.github/workflows/determine-workflow-runner.yml
     with: