Update version numbers in the README examples

Stop adding GitHub SSH keys (webfactory#171)

We need to fix the SSH keys shipped with this action:
https://github.blog/2023-03-23-we-updated-our-rsa-ssh-host-key/

But, we have another issue
(webfactory#108) with regards to host
keys: On self-hosted runners which are not ephemeral the known_host file
fills up with repeated entries, because every action run adds a new line
with the same host keys.

Also, on those machines, the old key will still be in the `known_hosts`
file.

IMHO this action should not be repsonsible for shipping SSH host keys,
that's too much responsibility.

This section in the code is a leftover from early days when GitHub
provided runners did not include SSH keys at all. For a long time
already, GH takes care of placing their SSH keys in their runner images.

For self-hosted runners, those people setting up the runner should fetch
and verify SSH keys themselves and put it into the `known_hosts` file.

I know this is a breaking change and is going to annoy users. But on the
other hand, there is no better opportunity to drop this feature than
with an emergency-style key revocation as today.

Closes webfactory#106, closes webfactory#129, closes webfactory#169, closes webfactory#170, closes webfactory#172.

Prepare a v0.7.0 release

Prepare a 0.6.0 release

Bump example version numbers in the README file

Prepare a 0.5.3 release

Update version numbers in README for the next bugfix release

Windows virtual environment: Use SSH binaries from the Git suite (web…

…factory#63)

* Use SSH binaries from the Git suite

* Try to kill the ssh-agent upon action termination on Windows as well

Prepare README for the upcoming 0.5.0 release

Update README for a 0.4.1 release