Fix GitHub Actions hashFiles() pattern for all platforms

- Use '**/Package.swift' pattern instead of 'Package.swift' alone
- Apply consistently across macOS and Linux jobs
- Should resolve 'failed to hash files' errors on GitHub runners

Author: coenttb

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .build
-          key: macos-swift62-spm-${{ hashFiles('Package.swift') }}
+          key: macos-swift62-spm-${{ hashFiles('**/Package.swift') }}
           restore-keys: |
             macos-swift62-spm-
 
@@ -69,7 +69,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .build
-          key: linux-swift62-spm-${{ hashFiles('Package.swift', 'Package@*.swift') }}
+          key: linux-swift62-spm-${{ hashFiles('**/Package.swift') }}
           restore-keys: linux-swift62-spm-
 
       # Note: swift test builds automatically in release mode
@@ -89,7 +89,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .build
-          key: linux-swift62-compat-spm-${{ hashFiles('Package.swift', 'Package@*.swift') }}
+          key: linux-swift62-compat-spm-${{ hashFiles('**/Package.swift') }}
           restore-keys: linux-swift62-compat-spm-
 
       # Note: swift test builds automatically