fix(ui): document token validity in key verification view (#9002)

Document that the token is only valid for a minute. Add a link to get a new token.

Resolves #8048

Co-authored-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9002
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: dawe <dawedawe@posteo.de>
Co-committed-by: dawe <dawedawe@posteo.de>

modules/test/utils.go

@@ -52,3 +52,9 @@ func MockProtect[T any](p *T) (reset func()) {
 func SleepTillNextSecond() {
 	time.Sleep(time.Second - time.Since(time.Now().Truncate(time.Second)))
 }
+
+// When this is called, sleep until the truncated unix time to a minute was
+// increased by one.
+func SleepTillNextMinute() {
+	time.Sleep(time.Minute - time.Since(time.Now().Truncate(time.Minute)))
+}