Bump @stylistic/eslint-plugin from 3.1.0 to 5.6.1

Bumps [@stylistic/eslint-plugin](https://github.com/eslint-stylistic/eslint-stylistic/tree/HEAD/packages/eslint-plugin) from 3.1.0 to 5.6.1.
- [Release notes](https://github.com/eslint-stylistic/eslint-stylistic/releases)
- [Changelog](https://github.com/eslint-stylistic/eslint-stylistic/blob/main/CHANGELOG.md)
- [Commits](https://github.com/eslint-stylistic/eslint-stylistic/commits/v5.6.1/packages/eslint-plugin)

---
updated-dependencies:
- dependency-name: "@stylistic/eslint-plugin"
  dependency-version: 5.6.1
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

internal/datastore/package.json

@@ -7,7 +7,7 @@
     "zod": "^4.1.11"
   },
   "devDependencies": {
-    "@stylistic/eslint-plugin": "^3.1.0",
+    "@stylistic/eslint-plugin": "^5.6.1",
     "@tsconfig/node22": "^22.0.2",
     "@types/jest": "^30.0.0",
     "@typescript-eslint/eslint-plugin": "^8.46.2",

internal/events/package.json

@@ -6,7 +6,7 @@
   "description": "Schemas for NHS Notify Supplier API events",
   "devDependencies": {
     "@stoplight/spectral-cli": "^6.15.0",
-    "@stylistic/eslint-plugin": "^3.1.0",
+    "@stylistic/eslint-plugin": "^5.6.1",
     "@tsconfig/node22": "^22.0.2",
     "@types/jest": "^29.5.14",
     "@typescript-eslint/eslint-plugin": "^8.27.0",

internal/helpers/package.json

@@ -4,7 +4,7 @@
   },
   "description": "Common helper utilities for NHS Notify Supplier API",
   "devDependencies": {
-    "@stylistic/eslint-plugin": "^3.1.0",
+    "@stylistic/eslint-plugin": "^5.6.1",
     "@tsconfig/node22": "^22.0.2",
     "@types/jest": "^29.5.14",
     "@typescript-eslint/eslint-plugin": "^8.27.0",