Bump de.rub.nds:protocol-toolkit-bom from 5.1.6 to 5.1.8

Bumps [de.rub.nds:protocol-toolkit-bom](https://github.com/tls-attacker/Protocol-Toolkit-BOM) from 5.1.6 to 5.1.8.
- [Commits](tls-attacker/Protocol-Toolkit-BOM@v5.1.6...v5.1.8)

---
updated-dependencies:
- dependency-name: de.rub.nds:protocol-toolkit-bom
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

pom.xml

@@ -4,7 +4,7 @@
     <parent>
         <groupId>de.rub.nds</groupId>
         <artifactId>protocol-toolkit-bom</artifactId>
-        <version>5.1.6</version>
+        <version>5.1.8</version>
     </parent>
 
     <artifactId>protocol-attacker</artifactId>