Optimize github action cache (#544)

* optimize github action cache

* fix

* refactor: improve github actions cache optimization (#3)

- move ccache configuration logic to dedicated action
- rename conanfile-changed to should-save-conan-cache for clarity

---------

Co-authored-by: Niq Dudfield <ndudfield@gmail.com>

.github/actions/xahau-ga-dependencies/action.yml

@@ -42,6 +42,26 @@ runs:
         SAFE_BRANCH=$(echo "${{ github.ref_name }}" | tr -c 'a-zA-Z0-9_.-' '-')
         echo "name=${SAFE_BRANCH}" >> $GITHUB_OUTPUT
 
+    - name: Check conanfile changes
+      if: inputs.cache_enabled == 'true'
+      id: check-conanfile-changes
+      shell: bash
+      run: |
+        # Check if we're on the main branch
+        if [ "${{ github.ref_name }}" == "${{ inputs.main_branch }}" ]; then
+          echo "should-save-conan-cache=true" >> $GITHUB_OUTPUT
+        else
+          # Fetch main branch for comparison
+          git fetch origin ${{ inputs.main_branch }}
+          
+          # Check if conanfile.txt or conanfile.py has changed compared to main branch
+          if git diff --quiet origin/${{ inputs.main_branch }}..HEAD -- '**/conanfile.txt' '**/conanfile.py'; then
+            echo "should-save-conan-cache=false" >> $GITHUB_OUTPUT
+          else
+            echo "should-save-conan-cache=true" >> $GITHUB_OUTPUT
+          fi
+        fi
+
     - name: Restore Conan cache
       if: inputs.cache_enabled == 'true'
       id: cache-restore-conan
@@ -76,7 +96,7 @@ runs:
           ..
 
     - name: Save Conan cache
-      if: inputs.cache_enabled == 'true' && steps.cache-restore-conan.outputs.cache-hit != 'true'
+      if: always() && inputs.cache_enabled == 'true' && steps.cache-restore-conan.outputs.cache-hit != 'true' && steps.check-conanfile-changes.outputs.should-save-conan-cache == 'true'
       uses: actions/cache/save@v4
       with:
         path: |