chore(deps): update dependency textlint to v15 (#181)

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

Author: renovate[bot]

package.json

@@ -17,7 +17,7 @@
     "@types/node": "^22.5.5",
     "highlight.js": "^11.10.0",
     "node-html-parser": "^7.0.0",
-    "textlint": "^14.2.0",
+    "textlint": "^15.0.0",
     "textlint-rule-preset-ja-spacing": "^2.4.3",
     "textlint-rule-prh": "^6.0.0",
     "vitepress": "^1.5.0",