Bump actions/setup-dotnet from 2 to 4

Bumps [actions/setup-dotnet](https://github.com/actions/setup-dotnet) from 2 to 4.
- [Release notes](https://github.com/actions/setup-dotnet/releases)
- [Commits](actions/setup-dotnet@v2...v4)

---
updated-dependencies:
- dependency-name: actions/setup-dotnet
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

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

@@ -21,7 +21,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Setup .NET
-        uses: actions/setup-dotnet@v2
+        uses: actions/setup-dotnet@v5
         with:
           global-json-file: global.json
 

.github/workflows/integration-tests.yml

@@ -42,7 +42,7 @@ jobs:
         fi
 
     - name: Setup .NET
-      uses: actions/setup-dotnet@v2
+      uses: actions/setup-dotnet@v5
       with:
         global-json-file: global.json
 
@@ -108,7 +108,7 @@ jobs:
         echo "PR_SHA=$(echo $prsha)" >> $GITHUB_ENV
 
     - name: Setup .NET
-      uses: actions/setup-dotnet@v2
+      uses: actions/setup-dotnet@v5
       with:
         global-json-file: global.json