Update actions/cache action to v6

Author: dependencyupdates[bot]

.github/workflows/build-samples-and-snippets.yml

@@ -19,7 +19,7 @@ jobs:
           global-json-file: global.json
       - name: Restore NuGet Cache
         id: nuget-cache-restore
-        uses: actions/cache/restore@v5
+        uses: actions/cache/restore@v6
         with:
           path: ~/.nuget/packages
           key: ${{ runner.os }}-nuget-${{ hashFiles('**/*.csproj') }}
@@ -30,7 +30,7 @@ jobs:
       - name: Save NuGet Cache
         id: nuget-cache-save
         if: always() && steps.nuget-cache-restore.outputs.cache-hit != 'true'
-        uses: actions/cache/save@v5
+        uses: actions/cache/save@v6
         with:
           path: ~/.nuget/packages
           key: ${{ steps.nuget-cache-restore.outputs.cache-primary-key }}

.github/workflows/copilot-setup-steps.yml

@@ -34,7 +34,7 @@ jobs:
 
       - name: Cache docstool
         id: cache-docstool
-        uses: actions/cache@v5.0.5
+        uses: actions/cache@v6.1.0
         with:
           path: |
             ~/.dotnet/tools/docstool

.github/workflows/publish-samples.yml

@@ -29,7 +29,7 @@ jobs:
            curl --connect-timeout 5 --max-time 15 --silent --show-error https://f.feedz.io/particular-software/packages/nuget/v3/packages/particular.docstool/index.json >> docstool-versions.json
       - name: Cache docstool
         id: cache-docstool
-        uses: actions/cache@v5.0.5
+        uses: actions/cache@v6.1.0
         with:
           path: |
              ~/.dotnet/tools/docstool

.github/workflows/validate-master.yml

@@ -28,7 +28,7 @@ jobs:
            echo "DOCSTOOL_VERSION=$(curl --connect-timeout 5 --max-time 15 --silent --show-error https://s3.amazonaws.com/particular.downloads/Particular.DocsTool/version.json)" >> $GITHUB_ENV
       - name: Cache docstool
         id: cache-docstool
-        uses: actions/cache@v5.0.5
+        uses: actions/cache@v6.1.0
         with:
           path: |
              ~/.dotnet/tools/docstool

.github/workflows/validate-pull-requests.yml

@@ -23,7 +23,7 @@ jobs:
            echo "DOCSTOOL_VERSION=$(curl --connect-timeout 5 --max-time 15 --silent --show-error https://s3.amazonaws.com/particular.downloads/Particular.DocsTool/version.json)" >> $GITHUB_ENV
       - name: Cache docstool
         id: cache-docstool
-        uses: actions/cache@v5.0.5
+        uses: actions/cache@v6.1.0
         with:
           path: |
              ~/.dotnet/tools/docstool