Run Lint and Tests on push to trunk branch

This change causes the "Lint" and "Unit and Integration Tests" workflows to only run on `push` events on the default branch (`trunk`).

This should avoid running redundant set of jobs on pull requests.

.github/workflows/go.yml

@@ -1,5 +1,9 @@
 name: Unit and Integration Tests
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - trunk
+  pull_request:
 
 permissions:
   contents: read

.github/workflows/lint.yml

@@ -1,6 +1,8 @@
 name: Lint
 on:
   push:
+    branches:
+      - trunk
     paths:
       - "**.go"
       - go.mod