[INTERNAL] Rename default branch to 'main'

JIRA: CPOUI5FOUNDATION-574

.github/workflows/dependabot-auto-merge.yml

@@ -2,7 +2,7 @@ name: Dependabot auto-merge
 on:
   pull_request:
     branches:
-      - master
+      - main
 
 permissions:
   contents: write

.github/workflows/github-ci.yml

@@ -2,9 +2,9 @@ name: GitHub CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   test:

.github/workflows/reuse-compliance.yml

@@ -2,9 +2,9 @@ name: REUSE
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   compliance-check:

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing to less-openui5
 
 In general the contributing guidelines of OpenUI5 also apply to this project. They can be found here:  
-https://github.com/SAP/openui5/blob/master/CONTRIBUTING.md
+https://github.com/SAP/openui5/blob/-/CONTRIBUTING.md
 
 Some parts might not be relevant for this project (e.g. the browser-specific requirements like jQuery, CSS and accessibility in the "Contribution Content Guidelines") and the contribution process is easier (pull requests will be merged directly on GitHub).