hadolint: skip .dockerfile-security.rego because it's not a dockerfile

[ioggstream]

I expect

• hadolint shouldn't process .dockerfile-security.rego since it's a .rego file
• moreover, it's a "hidden" file.

Instead

super-linter_1  | 2023-06-27 10:30:41 [INFO]   File:[/tmp/lint/.dockerfile-security.rego]
super-linter_1  | 2023-06-27 10:30:42 [ERROR]   Found errors in [hadolint] linter!
super-linter_1  | 2023-06-27 10:30:42 [ERROR]   Error code: 1. Command output:
super-linter_1  | ------
super-linter_1  | /tmp/lint/.dockerfile-security.rego:1:1 unexpected 'p' expecting '#', ADD, ARG, CMD, COPY, ENTRYPOINT, ENV, EXPOSE, FROM, HEALTHCHECK, LABEL, MAINTAINER, ONBUILD, RUN, SHELL, STOPSIGNAL, USER, VOLUME, WORKDIR, or end of input 
super-linter_1  | ------

[ioggstream]

@DrPlumcake

• proposal: rename .dockerfile-security.rego to .docker-security.rego
• consider https://github.com/par-tec/ml-playground/blob/main/.docker-security.rego for an easier, no-regexp, trusted repositories check