go.mod: bump gvisor

Updates #8043

Change-Id: Ia229ad4f28f2ff20e0bdecb99ca9e1bd0356ad8e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f