fix cta workflow to use platform (instead of branch) (#1929)

.github/workflows/test-cta.yml

@@ -21,7 +21,7 @@ env:
 jobs:
   create-recipe-with-npm:
     name: "node@${{ matrix.node }} + npm@${{ matrix.manager }}: ${{ matrix.recipe }}"
-    runs-on: ${{ github.event.inputs.branch || 'ubuntu' }}-latest
+    runs-on: ${{ github.event.inputs.platform || 'ubuntu' }}-latest
 
     strategy:
       fail-fast: false
@@ -47,7 +47,7 @@ jobs:
           npm-version: ${{ matrix.manager }}
           yarn-version: 1.22.5
       - name: install webkit2gtk
-        if: (github.event.inputs.branch || 'ubuntu') == 'ubuntu'
+        if: (github.event.inputs.platform || 'ubuntu') == 'ubuntu'
         run: |
           sudo apt-get update
           sudo apt-get install -y libgtk-3-dev libgtksourceview-3.0-dev webkit2gtk-4.0 libappindicator3-dev