Improve CI performance: NuGet caching + skip GenerateDocs on Windows (#1001)

- Add actions/cache@v4 for NuGet packages (keyed on Directory.Packages.props,
  global.json, and .config/dotnet-tools.json) to both workflow files.
  Subsequent runs restore the package cache, avoiding re-downloading packages.
- Add whenNot { envVar "RUNNER_OS" "Windows" } to the GenerateDocs stage in
  build.fsx so that the docs-generation step (fsdocs install + build) is
  skipped on Windows CI runners. Docs are only deployed from Linux, so this
  step adds no value on Windows and can take several minutes.

Closes #1001

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 2 people

.github/workflows/pull-requests.yml

@@ -24,6 +24,13 @@ jobs:
 
     steps:
     - uses: actions/checkout@v6
+    - name: Cache NuGet packages
+      uses: actions/cache@v4
+      with:
+        path: ~/.nuget/packages
+        key: ${{ runner.os }}-nuget-${{ hashFiles('Directory.Packages.props', 'global.json', '.config/dotnet-tools.json') }}
+        restore-keys: |
+          ${{ runner.os }}-nuget-
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v5
     - name: Run CI

.github/workflows/push-main.yml

@@ -16,6 +16,13 @@ jobs:
 
     steps:
     - uses: actions/checkout@v6
+    - name: Cache NuGet packages
+      uses: actions/cache@v4
+      with:
+        path: ~/.nuget/packages
+        key: ${{ runner.os }}-nuget-${{ hashFiles('Directory.Packages.props', 'global.json', '.config/dotnet-tools.json') }}
+        restore-keys: |
+          ${{ runner.os }}-nuget-
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v5
     - name: Run CI

build.fsx

@@ -62,6 +62,9 @@ pipeline "CI" {
     testStage
 
     stage "GenerateDocs" {
+        // Skip on Windows CI runners: docs are only deployed from Linux
+        whenNot { envVar "RUNNER_OS" "Windows" }
+
         run (fun _ ->
             Shell.cleanDir ".fsdocs"
             Shell.cleanDir ".packages")