refactor(flags): accept plural flag names through one normalize function

Every command accepts a flag's plural, such as --add-labels for
--add-label (D8), instead of per-command alias maps.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/pull_edit.go

@@ -143,10 +143,7 @@ pull request, or mark it as a draft or ready for review.`, Annotations: pullArgu
 	cmd.Flags().StringSliceVar(&reviewers.Remove.Users, "remove-reviewer", nil, "Withdraw review requests from users")
 	cmd.Flags().StringSliceVar(&reviewers.Add.Teams, "add-reviewer-team", nil, "Request reviews from teams of the repository's organization")
 	cmd.Flags().StringSliceVar(&reviewers.Remove.Teams, "remove-reviewer-team", nil, "Withdraw review requests from teams")
-	flagAliases(cmd, map[string]string{
-		"milestone-name": "milestone", "add-reviewers": "add-reviewer", "remove-reviewers": "remove-reviewer",
-		"add-reviewer-teams": "add-reviewer-team", "remove-reviewer-teams": "remove-reviewer-team",
-	})
+	flagAliases(cmd, map[string]string{"milestone-name": "milestone"})
 	for _, name := range []string{"add-reviewer", "remove-reviewer"} {
 		_ = cmd.RegisterFlagCompletionFunc(name, a.completeUsers())
 	}