Sync CI/CD to .NET 8

.github/workflows/publish.yaml

@@ -16,7 +16,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8.0.x
 
       - name: Generate the package
         # NOTE: As for the `${GITHUB_REF_NAME#v}` bit below, see https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables:~:text=branch%2D1.-,GITHUB_REF_NAME,-The%20short%20ref. We could've also done https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-environment-variable but since we're using this value in a single place, we don't need to make it an environment variable.

.github/workflows/test.yaml

@@ -16,7 +16,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: 7.0.x # NOTE: The `windows-latest` container already comes pre-installed with the .NET versions that we need, but we do need to use `setup-dotnet` (and pass it one of the versions — e.g. 7.0.x), so that the relevant binaries (e.g. `dotnet`) are actually added to PATH so we can use them. See https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#preinstalled-software and https://github.com/actions/setup-dotnet
+          dotnet-version: 8.0.x # NOTE: The `windows-latest` container already comes pre-installed with the .NET versions that we need, but we do need to use `setup-dotnet` (and pass it one of the versions — e.g. 7.0.x), so that the relevant binaries (e.g. `dotnet`) are actually added to PATH so we can use them. See https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#preinstalled-software and https://github.com/actions/setup-dotnet
 
       # TODO: Some .NET codebases with GitHub Actions workflows seem to run `dotnet restore`, `dotnet build` and `dotnet test` as separate steps. Why?
       - name: Run the tests