feat: rule.upstream support insecure_skip_verify

[wei840222]

Related issue(s)

https://github.com/ory/oathkeeper/issues/1201

Checklist

• [x] I have read the contributing guidelines.
• [ ] I have referenced an issue containing the design document if my change introduces a new feature.
• [x] I am following the contributing code guidelines.
• [x] I have read the security policy.
• [x] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got the approval (please contact [email protected]) from the maintainers to push the changes.
• [x] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have added or changed the documentation.

Further Comments

[CLAassistant]

All committers have signed the CLA.

[spaghettifunk]

Hi @aeneasr 👋 Would it be possible to merge this PR? It would be great 😄 Thanks for the hard work!