Fix the Sigstore inputs. Sigh.

Change-Id: I5ee5e77240952d4927959e2cdbe1b2f82cfa4d92
Reviewed-on: https://code-review.googlesource.com/c/re2/+/62971
Reviewed-by: Paul Wankadia <junyer@google.com>
Reviewed-by: Ash Liu <almquist@google.com>