ci: add -j to windows-cpu build, shorten docker job names

windows-cpu was the only job missing -j, running Ninja single-threaded.
Docker matrix jobs had auto-generated names concatenating all matrix
values; use display field for short human-readable names.

Author: Anbeeld

.github/workflows/release.yml

@@ -783,7 +783,7 @@ jobs:
             -DCMAKE_C_COMPILER_LAUNCHER=ccache ^
             -DCMAKE_CXX_COMPILER_LAUNCHER=ccache ^
             %CMAKE_ARGS%
-          cmake --build build --config Release
+          cmake --build build --config Release -j %NUMBER_OF_PROCESSORS%
 
       - name: ccache stats
         if: always()
@@ -1401,7 +1401,7 @@ jobs:
             release-notes.md
 
   docker-build:
-    name: Docker images
+    name: Docker (${{ matrix.config.display }})
     if: ${{ needs.release-meta.outputs.publish_docker == 'true' }}
     needs:
       - release-meta
@@ -1578,7 +1578,7 @@ jobs:
           if-no-files-found: error
 
   docker-merge:
-    name: Docker tags
+    name: Docker tags (${{ matrix.config.display }})
     if: ${{ needs.release-meta.outputs.publish_docker == 'true' }}
     needs:
       - release-meta