Update GitHub workflows

- Switch to 7.0.x

Author: rainboyan

.github/workflows/docs.yml

@@ -2,7 +2,7 @@ name: Grace Doc
 on:
   push:
     branches:
-      - 6.3.x
+      - 7.0.x
     paths:
       - 'src/docs/**'
 jobs:

.github/workflows/gradle.yml

@@ -2,10 +2,10 @@ name: Grace CI
 on:
   push:
     branches:
-      - 6.3.x
+      - 7.0.x
   pull_request:
     branches:
-      - 6.3.x
+      - 7.0.x
   workflow_dispatch:
 jobs:
   build:

.github/workflows/release-notes.yml

@@ -4,7 +4,7 @@ on:
     types: [closed,reopened]
   push:
     branches:
-      - 6.3.x
+      - 7.0.x
   workflow_dispatch:
 jobs:
   release_notes: