Update actions/cache action to v5.1.0 (#8377)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

.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@v5.1.0
         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@v5.1.0
         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@v5.1.0
         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@v5.1.0
         with:
           path: |
              ~/.dotnet/tools/docstool