fix!: fixed ssh key loading, removed support for specifying the ssh private key in plain text

[MarshallAsch]

Closes: #85
Closes: #84

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Describe the pull request:

• Removed support for specifying the content of the ssh key contents dirrectly, only private key file paths can be specified.
• will no longer pass the ssh private key to wikish in plain text
• will no longer copy the ssh private key to a temporary directory unless it needs to
• will mount the ssh priate key into the docker container when running in docker

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Checklist:

• Verify that the changes work as expected
• Verify that the changes work as expected when run using docker
• Update documentation / not applicable
• Update changelog / not applicable