Remove prefetch of 5.0.1-RC1 image in Server Pro E2E tests (#32991)

* Initial plan

* Remove prefetch of 5.0.1-RC1 image in Server Pro E2E tests

Agent-Logs-Url: https://github.com/overleaf/internal/sessions/db75e124-b3a1-463a-a41b-bd570af482ef

Co-authored-by: das7pad <17931887+das7pad@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: das7pad <17931887+das7pad@users.noreply.github.com>
GitOrigin-RevId: 9afbba3495706ed11a9392979138c06386b66c88

server-ce/test/Makefile

@@ -96,7 +96,6 @@ prefetch_old_4_2:
 
 prefetch_custom: prefetch_old_5_0
 prefetch_old_5_0:
-	docker pull $(IMAGE_TAG_PRO_BASE):5.0.1-RC1
 	docker pull $(IMAGE_TAG_PRO_BASE):5.0
 
 prefetch_custom: build_hotfix_5_5_5