fix: consolidate build steps to share NuGet cache

Each step runs in a fresh container, so NuGet packages restored in one
step aren't available in the next. Consolidating restore/build/test
into single steps.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.woodpecker/pr.yml

@@ -12,19 +12,9 @@ clone:
       lfs: false
 
 steps:
-  - name: restore
+  - name: build-and-test
     image: mcr.microsoft.com/dotnet/sdk:10.0
     commands:
       - dotnet restore
-
-  - name: build
-    image: mcr.microsoft.com/dotnet/sdk:10.0
-    commands:
-      - dotnet build --no-restore -c Release
-    depends_on: [restore]
-
-  - name: test
-    image: mcr.microsoft.com/dotnet/sdk:10.0
-    commands:
-      - dotnet test --no-build -c Release --logger "console;verbosity=detailed"
-    depends_on: [build]
+      - dotnet build -c Release
+      - dotnet test -c Release --logger "console;verbosity=detailed"