Feature: update cla and codecov configuration

Author: bochencwx

.github/.codecov.yml

@@ -2,3 +2,9 @@ comment:
   layout: "reach,diff,flags,tree"
   behavior: default
   require_changes: false
+
+coverage:
+  status:
+    project:
+      default:
+        threshold: 1%

.github/workflows/cla.yml

@@ -3,7 +3,7 @@ on:
   issue_comment:
     types: [created]
   pull_request_target:
-    types: [opened, closed, synchronize, reopened]
+    types: [opened, synchronize, reopened]
 
 # explicitly configure permissions, in case your GITHUB_TOKEN workflow permissions are set to read-only in repository settings
 permissions:
@@ -14,7 +14,7 @@ permissions:
 
 jobs:
   CLAAssistant:
-    runs-on: [self-hosted, trpc-cpp-ci]
+    runs-on: ubuntu-latest
     steps:
       - name: "CLA Assistant"
         if: (github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the CLA Document and I hereby sign the CLA') || github.event_name == 'pull_request_target'
@@ -28,4 +28,4 @@ jobs:
           path-to-signatures: 'signatures/${{ github.event.repository.name }}-${{ github.repository_id }}/cla.json'
           path-to-document: 'https://github.com/trpc-group/cla-database/blob/main/Tencent-Contributor-License-Agreement.md'
           # branch should not be protected
-          branch: 'main'
+          branch: 'main'