chore: Prepare for renaming default branch to main

Author: Muscraft

.github/workflows/audit.yml

@@ -10,7 +10,7 @@ on:
       - '**/Cargo.lock'
   push:
     branches:
-    - master
+    - main 
 
 env:
   RUST_BACKTRACE: 1

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
   push:
     branches:
-    - master
+    - main
 
 env:
   RUST_BACKTRACE: 1

.github/workflows/pre-commit.yml

@@ -5,7 +5,7 @@ permissions: {} # none
 on:
   pull_request:
   push:
-    branches: [master]
+    branches: [main]
 
 env:
   RUST_BACKTRACE: 1