Cache vcpkg dependencies in MSVC build

.github/workflows/build.yml

@@ -113,21 +113,38 @@ jobs:
         run: exit 1
   windows_msvc:
     runs-on: windows-latest
+    env:
+      VCPKG_BINARY_SOURCES: "clear;files,${{ github.workspace }}\\vcpkg-cache,readwrite"
     steps:
       - uses: actions/checkout@v6
-
-      - uses: ilammy/msvc-dev-cmd@v1
+
+      - name: Compute vcpkg cache key
+        id: vcpkg-key
+        shell: pwsh
+        run: |
+          $commit = git -C "$env:VCPKG_INSTALLATION_ROOT" rev-parse --short HEAD
+          "key=vcpkg-${{ runner.os }}-$env:ImageVersion-$commit" >> $env:GITHUB_OUTPUT
+
+      - name: Cache vcpkg binaries
+        uses: actions/cache@v6
+        with:
+          path: ${{ github.workspace }}/vcpkg-cache
+          key: ${{ steps.vcpkg-key.outputs.key }}
+          restore-keys: vcpkg-${{ runner.os }}-
 
       - name: Install dependencies
         run: |
           vcpkg install gettext libiconv libcsv libxlsxwriter zlib --triplet x64-windows
           vcpkg integrate install
 
+      - name: Setup MSBuild
+        uses: microsoft/setup-msbuild@v3
+
       - name: Fix library filename and paths for MSVC
         shell: pwsh
         run: |
-          $libDir = "C:\vcpkg\installed\x64-windows\lib"
-  
+          $libDir = "$env:VCPKG_INSTALLATION_ROOT\installed\x64-windows\lib"
+
           if (Test-Path "$libDir\iconv.lib") {
               Copy-Item "$libDir\iconv.lib" "$libDir\libiconv.lib" -Force
           }
@@ -160,8 +177,6 @@ jobs:
 
       - name: Test
         shell: pwsh
-        env:
-          PATH: C:\vcpkg\installed\x64-windows\bin;${{ env.PATH }}
         run: |
           # pwsh only fails the step on the last command's exit code, so
           # check each executable explicitly