Revert "Remove TAGS_REFSPEC if no_fetch_tags is true"

This reverts commit 9a94a95e.

Reason for revert: crbug/1199445

Original change's description:
> Remove TAGS_REFSPEC if no_fetch_tags is true
>
> Bug: 1188627
> Change-Id: I6ee14ee9976b9aab60ce409ddd17f018ad966055
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2797933
> Reviewed-by: Josip Sokcevic <sokcevic@google.com>
> Commit-Queue: Gavin Mak <gavinmak@google.com>

Bug: 1188627, 1199445
Change-Id: I776639709221d8e0505315c451f847d6cf592b62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2828772
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Auto-Submit: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>

recipes/recipe_modules/bot_update/resources/bot_update.py

@@ -711,8 +711,6 @@ def _git_checkout(sln, sln_dir, revisions, refs, no_fetch_tags, git_cache_dir,
                    '--cache-dir', git_cache_dir, url, '--reset-fetch-config'])
   if no_fetch_tags:
     populate_cmd.extend(['--no-fetch-tags'])
-    if TAGS_REFSPEC in refs:
-      refs.remove(TAGS_REFSPEC)
   for ref in refs:
     populate_cmd.extend(['--ref', ref])