chore(deps-dev): bump @salesforce/cli-plugins-testkit

Bumps [@salesforce/cli-plugins-testkit](https://github.com/salesforcecli/cli-plugins-testkit) from 1.5.28 to 1.5.31.
- [Release notes](https://github.com/salesforcecli/cli-plugins-testkit/releases)
- [Changelog](https://github.com/salesforcecli/cli-plugins-testkit/blob/main/CHANGELOG.md)
- [Commits](salesforcecli/cli-plugins-testkit@v1.5.28...v1.5.31)

---
updated-dependencies:
- dependency-name: "@salesforce/cli-plugins-testkit"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

yarn.lock

@@ -748,9 +748,9 @@
     safe-json-stringify "~1"
 
 "@salesforce/cli-plugins-testkit@^1.4.10":
-  version "1.5.28"
-  resolved "https://registry.yarnpkg.com/@salesforce/cli-plugins-testkit/-/cli-plugins-testkit-1.5.28.tgz#3c3ed8e99fc6365f149d4c5f2690b02166661d4b"
-  integrity sha512-BC/M24sg7IjiE/5aD7RazOVWNVG8kStYF3ze/zvKGIdRGjTjgBDwYR7LkT4VWIqH0y48ohSc9aQc0kJ3HsiC2Q==
+  version "1.5.31"
+  resolved "https://registry.yarnpkg.com/@salesforce/cli-plugins-testkit/-/cli-plugins-testkit-1.5.31.tgz#e18e06aa1739a5d527f43abedb6e28db4c1a420f"
+  integrity sha512-a/M+Vqsk2i7pFD27AMgtzaysxrXTT8tqnRbC0ByC/MlItywAU88QLovy7LOJEUtUvNx9oBakSUMsOdTUeO+G7w==
   dependencies:
     "@salesforce/core" "^2.24.0"
     "@salesforce/kit" "^1.5.13"