Skip CI tests for non-code changes (#673)

* Skip CI tests for non-code changes

- Add dorny/paths-filter to detect code changes
- Run actual tests only when code/build files change
- Add skip jobs to satisfy required status checks
- Reduces CI time for documentation-only changes

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add .scalafmt.conf to code change detection

- Ensures code format check runs when scalafmt config changes
- Important for maintaining consistent code formatting rules

* Add sbt launcher scripts to code change detection

- Includes sbt and sbt.bat in path filters
- Ensures tests run when build scripts are modified

* Remove test documentation file

- No longer needed for PR demonstration
- PR description already explains the changes

* Remove test-jdk skip jobs

- Remove unnecessary skip jobs for JDK tests
- Keep only code_format_skip for required status check

* Remove all skip jobs

- Remove code_format_skip job
- Simplify workflow to only run tests when code changes detected

---------

Co-authored-by: Claude <noreply@anthropic.com>

.github/workflows/test.yml

@@ -2,30 +2,38 @@ name: CI
 
 on:
   pull_request:
-    paths:
-      - '**.scala'
-      - '**.java'
-      - '**.sbt'
-      - '.github/workflows/*.yml'
-      - '**.so'
-      - '**.dll'
-      - 'src/main/resources/**'
-      - 'project/build.properties'
   push:
     branches:
       - master
       - main
-    paths:
-      - '**.scala'
-      - '**.java'
-      - '**.sbt'
-      - '.github/workflows/*.yml'
-      - 'src/main/resources/org/xerial/snappy/**'
-      - 'project/build.properties'
 
 jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      code: ${{ steps.filter.outputs.code }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            code:
+              - '**.scala'
+              - '**.java'
+              - '**.sbt'
+              - '.github/workflows/*.yml'
+              - '**.so'
+              - '**.dll'
+              - 'src/main/resources/**'
+              - 'project/build.properties'
+              - '.scalafmt.conf'
+              - 'sbt'
+              - 'sbt.bat'
   code_format:
     name: code format
+    needs: changes
+    if: ${{ needs.changes.outputs.code == 'true' }}
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -36,6 +44,8 @@ jobs:
       matrix:
         version: [ '8', '11', '17', '21' ]
     name: test jdk${{ matrix.version }}
+    needs: changes
+    if: ${{ needs.changes.outputs.code == 'true' }}
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4