lang/go125: Update to 1.25.7

Changes: go1.25.7 (released 2026-02-04) includes security fixes to the

go command and the crypto/tls package, as well as bug fixes to the
compiler and the crypto/x509 package. See the Go 1.25.7 milestone on our
issue tracker for details.

This is a direct commit to 2026Q1 because the Go framework has diverged.