Update dev dependencies and Dependabot schedule (#1731)

Bump @typescript-eslint/eslint-plugin and @typescript-eslint/parser to 8.44.0, and rollup to 4.50.2 in package.json and package-lock.json. Update Node.js version in Volta config to 20.19.5. Change Dependabot update interval from weekly to monthly for npm and GitHub Actions.

Author: coliff

.github/dependabot.yml

@@ -16,7 +16,7 @@ updates:
   - package-ecosystem: npm
     directory: '/website'
     schedule:
-      interval: weekly
+      interval: monthly
     versioning-strategy: increase
     groups:
       dependencies:
@@ -29,4 +29,4 @@ updates:
   - package-ecosystem: github-actions
     directory: '/'
     schedule:
-      interval: weekly
+      interval: monthly