[GEOS-10618] Assemble release geoserver_dir for Docker use

[jodygarnett]

A quick assembly to package up the release geoserver data directory for use with the official docker image. Zip structured with geoserver_dir folder to match Dockerfile.

I have manually created a zip for the most recent 2.21.1 release to allow documentation to be written:

• https://sourceforge.net/projects/geoserver/files/GeoServer/2.21.1/geoserver-2.21.1-data.zip/download

Checklist

• I have read the contribution guidelines.
• I have sent a Contribution Licence Agreement (not required for small changes, e.g., fixing typos in documentation).
• First PR targets the main branch (backports managed later; ignore for branch specific issues).
• All the build checks are green (see automated QA checks).

For core and extension modules:

• New unit tests have been added covering the changes.
• Documentation has been updated (if change is visible to end users).
• The REST API docs have been updated (when changing configuration objects or the REST controllers).
• There is an issue in the GeoServer Jira (except for changes that do not affect administrators or end users in any way).
• Commit message(s) must be in the form [GEOS-XYZWV] Title of the Jira ticket.
• Bug fixes and small new features are presented as a single commit.
• Each commit has a single objective (if there are multiple commits, each has a separate JIRA ticket describing its goal).

[jodygarnett]

website download page update geoserver/geoserver.github.io#130

[aaime]

Looks good to me, merging.

[aaime]

Not sure if you need a backport, if so you can add the backport labels even after the PR is merged, and the bot will try to do the backport PRs for you.

[jodygarnett]

Thanks, no harm in back porting I have added the label.