edit the contributing markdown because of the host of public GoB instead of Github

PiperOrigin-RevId: 607926204

CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6e4e0be..487f672 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -26,10 +26,7 @@
 
 ### Code reviews
 
-All submissions, including submissions by project members, require review. We
-use GitHub pull requests for this purpose. Consult
-[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
-information on using pull requests.
+All submissions, including submissions by project members, require review.
 
 ### Community guidelines
 
@@ -43,8 +40,3 @@
 with an outline of your planned change. \
 We will review your proposal and advise on the next steps you will need to take.
 
-1.  [Sign a Contributor License Agreement](https://cla.developers.google.com/)
-    if you haven't done so already. This only needs to be done once.
-1.  Open a pull request and add [timmatt-lee](https://github.com/timmatt-lee)
-    as a reviewer.
-