Skip duplicate actions.

.github/workflows/Linux_x86.yml

@@ -3,7 +3,17 @@ name: Linux_x86
 on: [push, pull_request]
 
 jobs:
+  prebuild:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        
   build:
+    needs: prebuild
+    if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
     runs-on: ubuntu-20.04
     steps:
     - name: Checkout

.github/workflows/Linux_x86_64.yml

@@ -3,7 +3,17 @@ name: Linux_x86_64
 on: [push, pull_request]
 
 jobs:
+  prebuild:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        
   build:
+    needs: prebuild
+    if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
     runs-on: ubuntu-20.04
     steps:
     - name: Checkout

.github/workflows/Linux_x86_64_SDL1.yml

@@ -3,7 +3,17 @@ name: Linux_x86_64_SDL1
 on: [push, pull_request]
 
 jobs:
+  prebuild:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        
   build:
+    needs: prebuild
+    if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
     runs-on: ubuntu-20.04
     steps:
     - name: Checkout

.github/workflows/MacOSX.yml

@@ -8,7 +8,17 @@ env:
   BUILD_TYPE: Release
 
 jobs:
+  prebuild:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        
   build:
+    needs: prebuild
+    if: ${{ needs.pre_job.outputs.should_skip != 'true' }}
     # The CMake configure and build commands are platform agnostic and should work equally
     # well on Windows or Mac.  You can convert this to a matrix build if you need
     # cross-platform coverage.