Bump golang.org/x/mod from 0.15.0 to 0.16.0 in /hack/update-go-mod

Bumps [golang.org/x/mod](https://github.com/golang/mod) from 0.15.0 to 0.16.0.
- [Commits](golang/mod@v0.15.0...v0.16.0)

---
updated-dependencies:
- dependency-name: golang.org/x/mod
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

hack/update-go-mod/go.mod

@@ -4,4 +4,4 @@ go 1.21.3
 
 toolchain go1.22.0
 
-require golang.org/x/mod v0.15.0
+require golang.org/x/mod v0.16.0

hack/update-go-mod/go.sum

@@ -1,2 +1,2 @@
-golang.org/x/mod v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
-golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/mod v0.16.0 h1:QX4fJ0Rr5cPQCF7O9lh9Se4pmwfwskqZfq5moyldzic=
+golang.org/x/mod v0.16.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=