Remove test branch from workflow

As directed by gu-dependency-graph-integrator [on the
PR](#174), I’m removing the
test branch trigger for the workflow after confirming that the workflow
ran correctly.

.github/workflows/sbt-dependency-graph.yaml

@@ -3,8 +3,7 @@ on:
   push:
     branches:
       - main
-      - sbt-dependency-graph-f558a69d3a4231c6
-  workflow_dispatch: 
+  workflow_dispatch:
 jobs:
   dependency-graph:
     runs-on: ubuntu-latest