use release version for yarn-plugin diffs

Co-Authored-by: MT Lewis <mtlewis@users.noreply.github.com>
Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>

Author: vinzscam

.github/workflows/release.yml

@@ -16,6 +16,7 @@ jobs:
     env:
       BACKSTAGE_APP_NAME: backstagediffapp
       VERSION: ${{ github.event.inputs.version }}
+      RELEASE_VERSION: ${{ github.event.inputs.releaseVersion }}
     steps:
       - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
 
@@ -61,24 +62,24 @@ jobs:
       - id: check_yarn_plugin_branch
         name: Check if yarn plugin branch already exists
         run: |
-          SKIP_DIFF="true" && [[ -z "$(git ls-remote --heads origin release/yarn-plugin/${VERSION})" ]] && SKIP_DIFF="false"
+          SKIP_DIFF="true" && [[ -z "$(git ls-remote --heads origin release/yarn-plugin/${RELEASE_VERSION})" ]] && SKIP_DIFF="false"
           echo "::set-output name=skip_create_diff::${SKIP_DIFF}"
       - name: Install yarn plugin
         run: |
           yarn plugin import https://versions.backstage.io/v1/tags/next/yarn-plugin
       - name: Run versions:bump to migrate to backstage:^ versions
         run: |
-          npx @backstage/cli@latest versions:bump --release ${{ github.event.inputs.releaseVersion }}
+          npx @backstage/cli@latest versions:bump --release $RELEASE_VERSION
         env:
           YARN_ENABLE_IMMUTABLE_INSTALLS: false
-      - name: Create branch for release ${VERSION} with yarn plugin installed
+      - name: Create branch for release ${RELEASE_VERSION} with yarn plugin installed
         if: steps.check_yarn_plugin_branch.outputs.skip_create_diff == 'false'
         run: |
-          git checkout -b release/yarn-plugin/${VERSION}
+          git checkout -b release/yarn-plugin/${RELEASE_VERSION}
           git add .
           git reset $BACKSTAGE_APP_NAME
-          git commit -m "Release ${VERSION}"
-          git push origin release/yarn-plugin/${VERSION}
+          git commit -m "Release ${RELEASE_VERSION}"
+          git push origin release/yarn-plugin/${RELEASE_VERSION}
       - run: echo "🍏 This job's status is ${{ job.status }}."
   diff:
     name: Create new diffs
@@ -110,9 +111,9 @@ jobs:
           mv _releases.json releases.json
       - name: Create new diffs for yarn plugin
         run: |
-          for version in $(jq -r 'to_entries |.[] | .value.createApp // .key'  < releases-yarn-plugin.json); do
-            echo "Creating yarn-plugin diffs between version $version and $NEW_VERSION "
-            git diff -U1 origin/release/yarn-plugin/$version..origin/release/yarn-plugin/$NEW_VERSION > diffs-yarn-plugin/$version..$NEW_VERSION.diff
+          for version in $(jq -r 'to_entries |.[] | .key'  < releases-yarn-plugin.json); do
+            echo "Creating yarn-plugin diffs between version $version and $RELEASE_VERSION"
+            git diff -U1 origin/release/yarn-plugin/$version..origin/release/yarn-plugin/$RELEASE_VERSION > diffs-yarn-plugin/$version..$RELEASE_VERSION.diff
           done
       - name: Add new version to releases-yarn-plugin.json
         run: |