Add logic to merge master first for unity upgrades

This step is wanted almost always and has been done manually by me before

Author: JohannesDeml

.github/workflows/upgrade-unity.yml

@@ -24,6 +24,11 @@ on:
         required: true
         type: boolean
         default: false
+      mergeMaster:
+        description: 'Merge master into branch'
+        required: true
+        type: boolean
+        default: true
       customParameters:
         description: 'Custom cli arguments'
         required: false
@@ -57,6 +62,22 @@ jobs:
           # Makes sure, that pushing new tags will trigger workflows
           token: ${{ secrets.PR_GITHUB_TOKEN }}
 
+      - name: Set git user
+        run: |
+          git status
+          git config --global user.email "$GIT_USER@users.noreply.github.com"
+          git config --global user.name "$GIT_USER"
+        env:
+          GIT_USER: ${{ github.actor }}
+
+      # Make sure the branch has the latest master changes in
+      - name: Merge master into current branch
+        if: ${{ inputs.mergeMaster }}
+        run: |
+          git fetch origin master --depth=1
+          git merge FETCH_HEAD
+          git push
+
       # Unity 2020 cache is not compatible with older versions
       - name: Unity Library Cache 2020 or higher
         if: ${{ !startsWith(inputs.unityVersion, '201') }}
@@ -115,14 +136,6 @@ jobs:
         if: ${{ !inputs.tagsOnly }}
         run: sudo rm -rf ./build
 
-      - name: Set git user
-        run: |
-          git status
-          git config --global user.email "$GIT_USER@users.noreply.github.com"
-          git config --global user.name "$GIT_USER"
-        env:
-          GIT_USER: ${{ github.actor }}
-
       - name: Render template
         if: ${{ !inputs.tagsOnly }}
         id: template