feat(docker): Support for Bearer token to access the Docker registry

[nielsbasjes]

Changes:

This is my first attempt to implement my suggestion as described here #10317

Essentially this allows using something like this to access a docker registry:

"hostRules": [{
  "matchHost": "eu.gcr.io",
  "token": "myReallySecretToken"
}],

Please nitpick this because it is my first code in this specific language.

Context:

The bearer token is the only way I can access the Google Container Registry.

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

NOTE: I wrote the documentation, but the way I documented this (using secrets in config.js) it does not seem to work as I thought it would.
See also my question about this: #10399

How I've tested my work (please tick one)

I have verified these changes via:

• Code inspection only, or
• Newly added unit tests, or
• No new tests but ran on a real repository, or
• Both unit tests + ran on a real repository

[HonkingGoose]

Some small fixes to start with.

[HonkingGoose]

Found some more changes we could make to tidy up the text some more.

By the way, if you want to apply multiple suggestions from a pull request review, go to the "Files changed" tab on GitHub where you can "batch multiple suggestions" into one commit.
That should take less clicks than from the "conversation tab".

[nielsbasjes]

Works on my machine:

[viceice]

@nielsbasjes PLease use those buttons to rerequest a review, so i get notified when you're done.

[HonkingGoose]

Documentation is nearly good to go, some things we can improve on some more.

[HonkingGoose]

The docs look good to me now!

[HonkingGoose]

Congratulations @nielsbasjes on getting this PR landed! 🚀

Well done everybody with the review comments/suggestions to clean this up! 😄

[renovate-release]

🎉 This PR is included in version 25.44.0 🎉

The release is available on:

• GitHub release
• 25.44.0

Your semantic-release bot 📦🚀