Fix custom 500 page rendering for render-time errors with experimental.advancedRouting astro/hono handlers - #17041

Failed to get file from ref "00f9f9f681096eaf51b9ec4c0add49c5170dd075:pnpm-lock.yaml": Error: Command failed: git show 00f9f9f681096eaf51b9ec4c0add49c5170dd075:pnpm-lock.yaml fatal: path 'pnpm-lock.yaml' exists on disk, but not in '00f9f9f681096eaf51b9ec4c0add49c5170dd075'