revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/t/t5514-fetch-multiple.sh

@@ -183,15 +183,4 @@ test_expect_success 'git fetch --all --tags' '
 	test_cmp expect test8/output
 '
 
-test_expect_success 'parallel' '
-	git remote add one ./bogus1 &&
-	git remote add two ./bogus2 &&
-
-	test_must_fail env GIT_TRACE="$PWD/trace" \
-		git fetch --jobs=2 --multiple one two 2>err &&
-	grep "preparing to run up to 2 tasks" trace &&
-	test_i18ngrep "could not fetch .one.*128" err &&
-	test_i18ngrep "could not fetch .two.*128" err
-'
-
 test_done