fix: remove broken cache save conditions for Conan

The check-conanfile-changes logic prevented cache saves on feature
branches unless conanfile changed, but this was broken because:
1. Cache keys don't include branch name (shared across branches)
2. S3 immutability makes this unnecessary (first-write-wins)
3. It prevented bootstrap saves on feature branches

Also removed unused safe-branch step (dead code from copy-paste)

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

@@ -47,33 +47,6 @@ outputs:
 runs:
   using: 'composite'
   steps:
-    - name: Generate safe branch name
-      if: inputs.cache_enabled == 'true'
-      id: safe-branch
-      shell: bash
-      run: |
-        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'
@@ -114,7 +87,7 @@ runs:
           ..
 
     - name: Save Conan cache
-      if: always() && inputs.cache_enabled == 'true' && steps.cache-restore-conan.outputs.cache-hit != 'true' && steps.check-conanfile-changes.outputs.should-save-conan-cache == 'true'
+      if: always() && inputs.cache_enabled == 'true' && steps.cache-restore-conan.outputs.cache-hit != 'true'
       uses: ./.github/actions/xahau-actions-cache-save
       with:
         path: ~/.conan2