nss: update to 3.78.

Change:

- Bug 1755264 - Added TLS 1.3 zero-length inner plaintext checks
  and tests, zero-length record/fragment handling tests.
- Bug 1294978 - Reworked overlong record size checks and added
  TLS1.3 specific boundaries.
- Bug 1763120 - Add ECH Grease Support to tstclnt
- Bug 1765003 - Add a strict variant of moz::pkix::CheckCertHostname.
- Bug 1166338 - Change SSL_REUSE_SERVER_ECDHE_KEY default to false.
- Bug 1760813 - Make SEC_PKCS12EnableCipher succeed
- Bug 1762489 - Update zlib in NSS to 1.2.12.

(wiz)