Run Gradle wrapper validation separately, only on Ubuntu

We also only need to run it on PRs

Author: DenWav

.github/workflows/pr.yml

@@ -0,0 +1,12 @@
+name: PR Validation
+on:
+  pull_request:
+    branches: ['*']
+
+jobs:
+  validation:
+    name: Validation
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: gradle/wrapper-validation-action@v1

.github/workflows/publish.yml

@@ -23,7 +23,6 @@ jobs:
           key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('gradle.properties') }}
           restore-keys: |
             ${{ runner.os }}-gradle-
-      - uses: gradle/wrapper-validation-action@v1
       - name: Setup publish token
         env:
           JETBRAINS_TOKEN: ${{ secrets.JETBRAINS_TOKEN }}

.github/workflows/test.yml

@@ -30,5 +30,4 @@ jobs:
           key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}-${{ hashFiles('gradle.properties') }}
           restore-keys: |
             ${{ runner.os }}-gradle-
-      - uses: gradle/wrapper-validation-action@v1
       - run: ./gradlew build --no-daemon --stacktrace