Bump build number to 15 and fix recipe style to make sure that bots update the build number

[traversaro]

If the build number is set via a variable, the variable should be named either build or build_number, see https://github.com/regro/cf-scripts/blob/bc57282361ba7437a46ee7ddde0783b94f1c1bc8/conda_forge_tick/update_recipe/build_number.py#L5-L11 .

Checklist

• [x] Used a personal fork of the feedstock to propose changes
• [x] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [x] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [x] Ensured the license file is being packaged.

[conda-forge-webservices[bot]]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[traversaro]

@conda-forge-admin, please rerender

[github-actions[bot]]

Hi! This is the friendly automated conda-forge-webservice.

I tried to rerender for you, but it looks like there was nothing to do.

This message was generated by GitHub actions workflow run https://github.com/conda-forge/gazebo-feedstock/actions/runs/9692679010.

[traversaro]

xref: https://github.com/conda-forge/jaxlib-feedstock/pull/267 .

[traversaro]

We need the patch in https://github.com/dartsim/dart/pull/1820 .

[github-actions[bot]]

Hi! This is the friendly conda-forge automerge bot!

I considered the following status checks when analyzing this PR:

• linter: passed
• azure: passed

Thus the PR was passing and merged! Have a great day!