Drop --no-build from pack step (#29)

The main csproj has an Analyzer ProjectReference to
StrongTypes.SourceGenerators. With --no-build, pack still needs to
resolve project references and invokes the Build target on the
generator project, which then fails with NETSDK1085 because NoBuild is
set. Letting pack perform a (no-op incremental) build sidesteps this.

The Pack step only runs on main pushes, so PR CI never exercised it —
both #25 and #26 merged green and broke main. A follow-up should make
this fail fast in PR CI.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: KaliCZ

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

@@ -50,7 +50,7 @@ jobs:
 
     - name: Pack
       if: github.ref == 'refs/heads/main' && github.event_name == 'push'
-      run: dotnet pack ./src/StrongTypes/StrongTypes.csproj -c $config --no-build -o out
+      run: dotnet pack ./src/StrongTypes/StrongTypes.csproj -c $config -o out
 
     - name: Upload NuGet package
       if: github.ref == 'refs/heads/main' && github.event_name == 'push'