As per the LGPL license, your ban on Fabric porting by third parties is invalid.

LGPL has a blanket allowance for modification and distribution, provided the original project and copyright remains credited and disclosed, the changes are stated, and the derivative work remains under the LGPL license (with some exceptions to usage via interface within a project).

If you wish to ban other developers from porting your mod to a separate mod loader, you will need to either relicense under a more restrictive license, or write a custom license which prohibits ports of your mod.

Note that, in order to change your license, under LGPL you will need to have the sign off of all involved contributors.

This means not only contributors to this repository, but also anyone who contributed to the original codebase:

https://github.com/ata4/dragon-mounts

Previous versions of your codebase before a change in license will still be licensed under the original LGPL license and are subject to its terms.

Thank you for your attention!

The original codebase is public domain.

Then the sign off of all contributors to the current repository will be needed.

you could always just say "please don't port to fabric" instead of just outright saying no to it, that's what some fabric modders to when they don't want their mod ported to forge, and allows them to keep their foss license's integrity intact

The issue has been addressed, Thank you for concerns.

@LagoonTheAbyssal, @qsefthuopq, and @KhottyManatee55 do not appear to have consented to the relicensing.

[The contributors listed] do not appear to have consented to the relicensing.

yep, they are free to submit a DMCA request to GitHub because their copyright over the code is being violated

You guys are clearly very mistaken on the reliability of Wolf.
He messaged every user involved and got consent to change the license, this includes me. If you truly think that I have not consented, you are vastly mistaken. Just because we haven't posted our consenting to the change of license publicly, does not mean that we have not approved. If we haven't, I'm sure any and all of us would speak up about it. Thank you for your concerns, however.
If truly need be, I'll happily sign off to something public about consent, but he did reach out to everyone involved.