finish master to main migration

Author: reyang

.github/workflows/ci.yml

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

buildscripts/pre_release.sh

@@ -50,7 +50,7 @@ if [ ! grep -q "^\#\# \[Unreleased\]$" $changelog_file ]; then
     exit 1
 fi
 
-git checkout -b pre_release_${tag} master
+git checkout -b pre_release_${tag} main
 if [ $? -ne 0 ]; then
     echo "Error: Cannot create release branch. Ensure you have sufficient permissions to repo and try again."
     exit 1
@@ -67,5 +67,5 @@ fi
 git add CHANGELOG.md
 git commit -m "Prepare for releasing ${tag}"
 
-echo "Now validate the chages using git diff master, create the ${tag} and push changes to upstream"
+echo "Now validate the changes using git diff main, create the ${tag} and push changes to upstream"
 echo