Split dotnet run into build + run --no-build in CI

Separate the restore/build step from the generator execution so CI
logs clearly show where time is spent (build vs runtime).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: meziantou

.github/workflows/ci.yml

@@ -23,7 +23,8 @@ jobs:
       uses: actions/setup-dotnet@v5
     - name: Copy README before generation
       run: Copy-Item README.md README.md.before
-    - run: dotnet run --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet build Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet run --no-build --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
     - name: Validate README is up to date
       run: |
         # Normalize line endings for comparison
@@ -45,7 +46,8 @@ jobs:
     - uses: actions/checkout@v6
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v5
-    - run: dotnet run --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet build Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet run --no-build --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
     - run: dotnet pack Meziantou.Polyfill --configuration Release
 
     - uses: actions/upload-artifact@v7
@@ -96,7 +98,8 @@ jobs:
     - uses: actions/checkout@v6
     - name: Setup .NET
       uses: actions/setup-dotnet@v5
-    - run: dotnet run --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet build Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet run --no-build --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
     - run: dotnet test Meziantou.Polyfill.SourceGenerator.Tests
 
   tests:
@@ -112,7 +115,8 @@ jobs:
         dotnet-version: |
             9.0.x
             8.0.x
-    - run: dotnet run --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet build Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
+    - run: dotnet run --no-build --project Meziantou.Polyfill.Generator/Meziantou.Polyfill.Generator.csproj
     - run: dotnet test Meziantou.Polyfill.Tests
 
   deploy: