ci: Fix macOS hashFiles() failure in Homebrew cache

Replace hashFiles('.github/workflows/ci.yml') with static version key
to fix intermittent "Fail to hash files under directory" error on
macOS runners (GitHub Actions issues #4134, #3015).

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

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

Author: gto90

.github/workflows/ci.yml

@@ -51,7 +51,7 @@ jobs:
             ~/Library/Caches/Homebrew
             /opt/homebrew/Cellar
             /opt/homebrew/opt
-          key: ${{ github.job }}-brew-${{ hashFiles('.github/workflows/ci.yml') }}
+          key: ${{ github.job }}-brew-v1
           restore-keys: ${{ github.job }}-brew-
 
       - name: Install Homebrew packages
@@ -156,7 +156,7 @@ jobs:
             ~/Library/Caches/Homebrew
             /opt/homebrew/Cellar
             /opt/homebrew/opt
-          key: ${{ github.job }}-brew-${{ hashFiles('.github/workflows/ci.yml') }}
+          key: ${{ github.job }}-brew-v1
 
   linux-native:
     name: 'Ubuntu 22.04 native, Qt GUI, with depends, unit tests, functional tests'