Bump org.bouncycastle:bcprov-jdk18on from 1.76 to 1.78 (#941)

* Bumps [org.bouncycastle:bcprov-jdk18on](https://github.com/bcgit/bc-java) from 1.76 to 1.78.
- [Changelog](https://github.com/bcgit/bc-java/blob/main/docs/releasenotes.html)
- [Commits](https://github.com/bcgit/bc-java/commits)

updated-dependencies:
- dependency-name: org.bouncycastle:bcprov-jdk18on
  dependency-type: direct:production

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Les Hazlewood <121180+lhazlewood@users.noreply.github.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ This patch release:
   used to construct a `Jws` instance (instead of JJWT's default decoder). See
   [Issue 947](https://github.com/jwtk/jjwt/issues/947).
 * Fixes a decompression memory leak in concurrent/multi-threaded environments introduced in 0.12.0 when decompressing JWTs with a `zip` header of `GZIP`. See [Issue 949](https://github.com/jwtk/jjwt/issues/949).
+* Upgrades BouncyCastle to 1.78.
 
 ### 0.12.5