fix: avoid expensive globwalk in examples (#7238)
### Description
Q: how long would a `turbo lint` call would take in our repository?
A: 13 minutes
12 minutes of that is collecting inputs for
`turborepo-examples:lint-prettier` which it inherits from the root
definition.
<img width="1613" alt="Screenshot 2024-02-02 at 11 36 38 AM"
src="https://github.com/vercel/turbo/assets/4131117/6edaf9c4-5e18-40d1-a55c-63f05f633bf5">
This PR overrides that input list and now it only takes ~200ms to do
nothing.
### Testing Instructions
<img width="1050" alt="Screenshot 2024-02-02 at 11 39 08 AM"
src="https://github.com/vercel/turbo/assets/4131117/c8b22f67-fe40-4d8c-9f87-db52d12a51e0">
Closes TURBO-2231
