Bump org.bouncycastle:bcpkix-jdk18on from 1.80 to 1.81

Bumps [org.bouncycastle:bcpkix-jdk18on](https://github.com/bcgit/bc-java) from 1.80 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: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]

engine/build.gradle.kts

@@ -75,7 +75,7 @@ dependencies {
   implementation("de.gesellix:docker-filesocket:2025-05-16T22-45-00")
   testImplementation("de.gesellix:testutil:2025-05-16T22-30-00")
 
-  implementation("org.bouncycastle:bcpkix-jdk18on:1.80")
+  implementation("org.bouncycastle:bcpkix-jdk18on:1.81")
 
   testImplementation("org.spockframework:spock-core:2.3-groovy-4.0")
   testRuntimeOnly("net.bytebuddy:byte-buddy:1.17.5")