Integrate gitlab-ci/remove-alphaplan and 3 more

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Commit: seco-ne/yocto/infrastructure/gitlab-ci@6f773de5

Remove Alphaplan stage

We do not use Alphaplan anymore. Remove everything Alphaplan related
stuff from the pipeline.

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Commit: seco-ne/yocto/infrastructure/gitlab-ci@56bd1900

Confluence: add helper script to get page content

This can be helpful if something is configurable in the GUI editor and
we can't figure out to do the same thing via the API.

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Commit: seco-ne/yocto/infrastructure/gitlab-ci@c3b794c6

Confluence: enforce fixed page width on creation

On page creation via the API, the page always seems to be created with
full width, even if "full_width=False" is set. Update the page right
after creating it in order to correctly set it to fixed width.

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Commit: seco-ne/yocto/infrastructure/gitlab-ci@82053a2f

Confluence: set width for download table columns