Fix code scanning alert - Incorrect suffix check

[golles]

Tracking issue for:

• https://github.com/golles/mock-yaml-secrets-action/security/code-scanning/1

This issue is coming from https://github.com/koichik/node-tunnel/

❯ npm ls tunnel
mock-yaml-secrets-action@1.0.0 mock-yaml-secrets-action
└─┬ @actions/core@1.10.0
  └─┬ @actions/http-client@2.1.0
    └── tunnel@0.0.6

There is a PR that replaces that library: actions/toolkit#1432