chore(deps): update dependency knip to v6 (#5828)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Mark Wiemer <markwiemer@outlook.com>

Author: renovate[bot]

.knip.jsonc

@@ -1,5 +1,5 @@
 {
-  "$schema": "https://unpkg.com/knip@5/schema-jsonc.json",
+  "$schema": "https://unpkg.com/knip@6/schema-jsonc.json",
   "entry": [
     "bin/mocha.js!",
     "bin/_mocha!",

docs/.knip.jsonc

@@ -1,7 +1,7 @@
 {
-  "$schema": "https://unpkg.com/knip@5/schema-jsonc.json",
+  "$schema": "https://unpkg.com/knip@6/schema-jsonc.json",
   // Entry points marked with ! are analyzed but not reported as unused
-  "entry": ["src/content/**/*.mdx!"],
+  "entry": ["src/content/**/*.{mdx,ts}!"],
   "project": ["src/**/*.{ts,js,mjs,cjs,astro}"],
   "astro": {
     "config": "astro.config.ts",