[Bug] Backport fix for FW RTL approach bug to 1.16

[msberk]

Describe the bug

Please see #25587 for the PR to main, and #25436 for a description of the original issue.

[msberk]

Realized in my early morning that I misunderstood the original backport issue request from @hamishwillee. I think I have edited it to be appropriate but unfortunately it is retaining the Documentation label if someone wants to drop that.

@dagar @sfuhrer for review.

[hamishwillee]

@msberk Thanks for this - it does what I need.

Note though, if you actually want this backported, you're best bet is to create a PR that makes the actual changes in v1.16 that were made in the original PR, along with test code that verifies it. This greatly increases the chance that a fix will go in, since otherwise who do you think will do the work?

[msberk]

@hamishwillee I'm waiting until the code is merged to main in case there are any other comments on it, then I will make a PR back to 1.16.

• Fix position setpoint update logic in Mission RTL #25600

[msberk]

Closed by #25861