Upgrade amber/web from Dropwizard 1.3.23 to 4.0.7

### Task Summary

`amber/build.sbt` is pinned to Dropwizard `1.3.23` (Java EE 8, javax namespace, last release 2020). The five microservices in this repo are on Dropwizard `4.0.7` (Jakarta EE 9+, jakarta namespace). The split blocks unification of the JWT auth filter (#4901 family — two `JwtAuthFilter` implementations, two challenge formats, two annotation namespaces) and pins amber to several unmaintained Dropwizard-1.x-only third-party bundles.

The work is scoped to `amber/src/main/scala/org/apache/texera/web/` (125 files). The engine (`amber/src/main/scala/org/apache/texera/amber/`, 152 files) has zero javax / Dropwizard imports and does not need to change for the upgrade to land — except for four reverse-dependency leaks that must be cleaned up first (the prereq sub-issue).

Acceptance: `amber/build.sbt` declares `dropwizardVersion = "4.0.7"`, the toastshaman / file-assets / redirect / liveperson dropwizard-websockets dependencies are removed, `sbt WorkflowExecutionService/test` is green, and `amber/src/main/scala/org/apache/texera/web/auth/JwtAuth.scala` is gone.

Context: PR #5404 / #5421 hardened the in-house filter; the dual-filter status quo persists only because this upgrade is open.

### Task Type

- [x] Refactor / Cleanup