Update workflows

Author: JerBouma

.github/workflows/linting.yml

@@ -6,6 +6,7 @@ on:
   push:
     branches:
       - 'main'
+      - 'develop'
 
 jobs:
   code-linting:

.github/workflows/unit_tests.yml

@@ -1,6 +1,12 @@
 name: Run Unit Tests 
 
-on: [push]  
+on:
+  pull_request:
+    types: [opened, synchronize, edited]
+  push:
+    branches:
+      - 'main'
+      - 'develop'
 
 jobs:  
   build: