fix: update CLA link to correct URL (#21423)

Author: Oreoxmt

.github/pull_request_template.md

@@ -7,7 +7,7 @@ https://github.com/pingcap/docs/tree/master/resources/doc-templates
 
 ### First-time contributors' checklist <!--Remove this section if you're not a first-time contributor.-->
 
-- [ ] I've signed [**Contributor License Agreement**](https://cla-assistant.io/pingcap/docs) that's required for repo owners to accept my contribution.
+- [ ] I've signed the [**Contributor License Agreement**](https://cla.pingcap.net/pingcap/docs), which is required for the repository owners to accept my contribution.
 
 ### What is changed, added or deleted? (Required)
 

CONTRIBUTING.md

@@ -67,7 +67,7 @@ Please perform the following steps to create your Pull Request to this repositor
 
 ### Step 0: Sign the CLA
 
-Your Pull Requests can only be merged after you sign the [Contributor License Agreement](https://cla-assistant.io/pingcap/docs) (CLA). Please make sure you sign the CLA before continuing.
+To have your pull requests merged, you must sign the [Contributor License Agreement](https://cla.pingcap.net/pingcap/docs) (CLA). Please make sure you sign it before continuing.
 
 ### Step 1: Fork the repository