fix: mock-plugin/pom.xml to reduce vulnerabilities (#69)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-COMMONSBEANUTILS-460111

Signed-off-by: rajapandi.m <rajapandi.m@technoforte.co.in>
Co-authored-by: snyk-bot <snyk-bot@snyk.io>