ci: remove Percy retry

Created by: valerybugakov

Context

Restarting individual Percy's steps yields errors because it leads to duplicate snapshot issues and is incompatible with the PERCY_PARALLEL_TOTAL that we use to finalize Percy's build. The whole Percy pipeline should be restarted.

We should solve the underlying issue that caused retries: Error: Timeout getting coverage from https://sourcegraph.test:3443/users/test/settings/profile. Will look into it in a separate PR.

Test plan

n/a