Bump requests-mock-flask from 2026.2.16 to 2026.4.2

Bumps [requests-mock-flask](https://github.com/adamtheturtle/requests-mock-flask) from 2026.2.16 to 2026.4.2.
- [Release notes](https://github.com/adamtheturtle/requests-mock-flask/releases)
- [Changelog](https://github.com/adamtheturtle/requests-mock-flask/blob/main/CHANGELOG.rst)
- [Commits](adamtheturtle/requests-mock-flask@2026.02.16...2026.04.02)

---
updated-dependencies:
- dependency-name: requests-mock-flask
  dependency-version: 2026.4.2
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pyproject.toml

@@ -80,7 +80,7 @@ optional-dependencies.dev = [
     "pytest-retry==1.7.0",
     "pytest-xdist==3.8.0",
     "pyyaml==6.0.3",
-    "requests-mock-flask==2026.2.16",
+    "requests-mock-flask==2026.4.2",
     "ruff==0.15.8",
     # We add shellcheck-py not only for shell scripts and shell code blocks,
     # but also because having it installed means that ``actionlint-py`` will