CI: Limit publishing steps to master branch

.github/workflows/build.yml

@@ -2,8 +2,7 @@ name: Build
 
 on:
   push:
-    branches:
-      - master
+    branches: [master]
   pull_request: {}
   merge_group: {}
 
@@ -41,6 +40,7 @@ jobs:
         git fetch --unshallow
         make -j2 duke3d sw blood rr exhumed kenbuild tools SDLCONFIG= ${{matrix.opt}}
     - name: prepare artifacts
+      if: github.ref == 'refs/heads/master'
       run: |
         mkdir -p upload/nblood/
         mkdir -p upload/rednukem/
@@ -49,6 +49,7 @@ jobs:
         cp rednukem.exe upload/rednukem/
         cp pcexhumed.exe upload/pcexhumed/
     - uses: actions/upload-artifact@v2
+      if: github.ref == 'refs/heads/master'
       with:
         name: ${{matrix.label}}
         path: upload/

.github/workflows/publish.yml

@@ -2,11 +2,10 @@ name: Publish
 
 # Only trigger, when the build workflow succeeded
 on:
-  workflow_dispatch:
   workflow_run:
     workflows: [Build]
-    types:
-      - completed
+    types: [completed]
+    branches: [master]
 
 jobs:
   release: