🤖 Chore: remove deprecated appendListOptionsWithCursorToSQL (#44385)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
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**Related issue:** Resolves #44723

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.

- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
- [x] If paths of existing endpoints are modified without backwards
compatibility, checked the frontend/CLI for any necessary changes

## Testing

- [x] Added/updated automated tests
- [x] Where appropriate, [automated tests simulate multiple hosts and
test for host
isolation](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/reference/patterns-backend.md#unit-testing)
(updates to one hosts's records do not affect another)

- [ ] QA'd all new/changed functionality manually


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Strengthened validation of sorting/order parameters across many list
and cursor-based endpoints — unsupported sort keys now return explicit
errors and prevent unsafe queries.
* Labels listing: label-list pagination query name changed; ordering by
host_count is rejected when host counts are disabled (validated at
request parsing).

* **Tests**
* Added/expanded tests covering allowed order keys, rejection of unknown
keys, and pagination behavior for multiple listing APIs.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Lucas Manuel Rodriguez <lucas@fleetdm.com>

changes/cleanup-list-opts

@@ -0,0 +1 @@
+* Improved validation of order parameters on list endpoints