Release 1.4.0: restore netstandard2.0, add trusted-publishing NuGet workflow

.github/workflows/build-and-publish.yml

@@ -0,0 +1,69 @@
+name: build and publish
+
+on:
+  push:
+    branches: [master]
+    tags: ["v*"]
+  pull_request:
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: build and test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-dotnet@v6
+        with:
+          dotnet-version: 10.0.x
+
+      - name: Test
+        run: dotnet test EppLib.UnitTests/EppLib.UnitTests.csproj -c Release
+
+      - name: Check tag matches package version
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: |
+          version=$(dotnet msbuild EppLib/EppLib.csproj -getProperty:Version)
+          if [ "v$version" != "$GITHUB_REF_NAME" ]; then
+            echo "Tag $GITHUB_REF_NAME does not match package version $version"
+            exit 1
+          fi
+
+      - name: Pack
+        run: dotnet pack EppLib/EppLib.csproj -c Release -o artifacts
+
+      - uses: actions/upload-artifact@v7
+        with:
+          name: nupkg
+          path: artifacts/*.nupkg
+
+  publish:
+    name: publish to NuGet
+    needs: build
+    if: startsWith(github.ref, 'refs/tags/v')
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v8
+        with:
+          name: nupkg
+          path: artifacts
+
+      - uses: actions/setup-dotnet@v6
+        with:
+          dotnet-version: 10.0.x
+
+      # Trusted publishing: exchanges the GitHub OIDC token for a short-lived NuGet API key.
+      - name: NuGet login
+        id: login
+        uses: NuGet/login@v1
+        with:
+          user: ademar
+
+      - name: Push
+        run: dotnet nuget push "artifacts/*.nupkg" --api-key "${{ steps.login.outputs.NUGET_API_KEY }}" --source https://api.nuget.org/v3/index.json