Address Coq 8.13 deprecation warnings

[#11 (diff)](https://github.com/coq-community/dblib/pull/11/files#diff-7bc0f432942f548a20da329bb4e45e21faeeb897fe1d7e0bc26d20210a6e38f1R3) silenced two new deprecation warnings:
- `deprecated-hint-without-locality`
- `deprecated-instance-without-locality`

We have many hints and instances that use default locality. Look into explicitly setting locality to `local` or `export` wherever possible