feat(deps): Update singer-sdk requirement from ~=0.41.0 to ~=0.42.1

Updates the requirements on [singer-sdk](https://github.com/meltano/sdk) to permit the latest version.
- [Release notes](https://github.com/meltano/sdk/releases)
- [Changelog](https://github.com/meltano/sdk/blob/main/CHANGELOG.md)
- [Commits](meltano/sdk@v0.41.0...v0.42.1)

---
updated-dependencies:
- dependency-name: singer-sdk
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -36,7 +36,7 @@ dynamic = [
 dependencies = [
   "requests>=2,<3",
   "requests-cache>=1,<2",
-  "singer-sdk~=0.41.0",
+  "singer-sdk~=0.42.1",
 ]
 optional-dependencies.dev = [
   "tap-clinicaltrials[testing,typing]",