ci: remove save-always, remove old vcpkg cache key, flush vcpkg caches

.github/workflows/build.yaml

@@ -44,18 +44,16 @@ jobs:
       - name: Cache vcpkg
         uses: actions/cache@v4
         with:
-          save-always: true # deprecated
           path: target/vcpkg
-          key: vcpkg-${{ runner.os }}-${{ matrix.target }}-${{ hashFiles('Cargo.toml', 'Cargo.lock') }}
+          key: A-vcpkg-${{ runner.os }}-${{ matrix.target }}-${{ hashFiles('Cargo.toml', 'Cargo.lock') }}
           restore-keys: |
-            ${{ runner.os }}-vcpkg
+            A-vcpkg-${{ runner.os }}-${{ matrix.target }}-
-            vcpkg-${{ runner.os }}-${{ matrix.target }}-
 
       - name: Vcpkg Linux Dependencies
         if: runner.os == 'Linux'
         run: |
           sudo apt-get update
-          sudo apt-get install -y build-essential gettext libltdl-dev zlib1g-dev
+          sudo apt-get install -y libltdl-dev
 
       - name: Vcpkg
         run: |