[20410] Remove Data-Sharing option (backport #100)

[mergify]

Shapes Demo has never worked in data-sharing mode (because the Shape type contains an unbounded string).
This PR removes the data-sharing option from the documentation, as it is never used.

@Mergifyio backport 2.6.x 2.10.x 2.12.x 2.13.x

Related implementation PR:

• [20410] Remove Data-Sharing option  ShapesDemo#113

  ---

  This is an automatic backport of pull request [20410] Remove Data-Sharing option #100 done by Mergify.

[mergify]

Cherry-pick of 57f1a58 has failed:

On branch mergify/bp/2.12.x/pr-100
Your branch is up to date with 'origin/2.12.x'.

You are currently cherry-picking commit 57f1a58.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   docs/first_steps/first_steps.rst

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   docs/01-figures/participant.png
	both modified:   docs/01-figures/participant_ros_enabled.png
	both modified:   docs/01-figures/tcp_client_options.png
	both modified:   docs/01-figures/tcp_lan_server_options.png
	both modified:   docs/01-figures/tcp_wan_server_options.png

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[richiprosima]

Build status: