(maint) Update to Mend on the 7.x branch

Snyk is being replaced by Mend, and based upon our current code each branch
gets it's own version of the workflow file.

Author: cthorn42

.github/workflows/mend.yaml

@@ -0,0 +1,34 @@
+---
+name: Mend Monitor
+on:
+  push:
+    branches:
+      - 7.x
+jobs:
+  mend_monitor:
+    if: ${{ github.repository_owner == 'puppetlabs' }}
+    runs-on: ubuntu-latest
+    name: Mend Monitor
+    steps:
+      - name: Checkout current PR
+        uses: actions/checkout@v3
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.7
+      - name: Create lock
+        run: bundle lock
+      - uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+      - name: Download Mend
+        run: curl -o wss-unified-agent.jar https://unified-agent.s3.amazonaws.com/wss-unified-agent.jar
+      - name: Run Mend
+        run: java -jar wss-unified-agent.jar
+        env:
+          WS_APIKEY: ${{ secrets.MEND_API_KEY }}
+          WS_WSS_URL: https://saas-eu.whitesourcesoftware.com/agent
+          WS_USERKEY: ${{ secrets.MEND_TOKEN }}
+          WS_PRODUCTNAME: Puppet Agent
+          WS_PROJECTNAME: ${{ github.event.repository.name }}