Bump bouncy-castle.version from 1.78.1 to 1.81

Bumps `bouncy-castle.version` from 1.78.1 to 1.81.

Updates `org.bouncycastle:bcprov-jdk18on` from 1.78.1 to 1.81
- [Changelog](https://github.com/bcgit/bc-java/blob/main/docs/releasenotes.html)
- [Commits](https://github.com/bcgit/bc-java/commits)

Updates `org.bouncycastle:bcpkix-jdk18on` from 1.78.1 to 1.81
- [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-version: '1.81'
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.bouncycastle:bcpkix-jdk18on
  dependency-version: '1.81'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -50,7 +50,7 @@
         <secure-api-gateway.version>4.0.4</secure-api-gateway.version>
         <openig.version>2024.11.0</openig.version>
         <nimbus-jose.version>9.40</nimbus-jose.version>
-        <bouncy-castle.version>1.78.1</bouncy-castle.version>
+        <bouncy-castle.version>1.81</bouncy-castle.version>
         <maven-resources-plugin.version>3.1.0</maven-resources-plugin.version>
     </properties>