Bump `validator` dependency to 13.7.0 (#3566)
Bump `validator` dependency to 13.7.0 (#3566)

`validator` 13.6 has a security advisory:
https://github.com/advisories/GHSA-qgmg-gppg-76g5

I don't think it really affects us but it's making annoying noise in the repo.
matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc