Remove v in git remote command in dev installation (#6688)

Update docs/dev/development.md - fix recommended git command
to look up branches on the upstream remote.

Fixes #6686

docs/dev/development.md

@@ -71,7 +71,7 @@ This remote can be used to merge changes from Cirq's main repository into your l
     ```
 
     You can check the branches that are on the ```upstream``` remote by
-    running ```git remote -va``` or ```git branch -r```.
+    running `git ls-remote --heads upstream` or `git branch -r`.
 Most importantly you should see ```upstream/main``` listed.
 1. Merge the upstream main into your local main so that it is up to date.