Bump libsecp256k1 from 0.3.5 to 0.7.0 in /fuzz/storage-proof
Bumps [libsecp256k1](https://github.com/paritytech/libsecp256k1) from 0.3.5 to 0.7.0.
- [Release notes](https://github.com/paritytech/libsecp256k1/releases)
- [Changelog](https://github.com/paritytech/libsecp256k1/blob/master/CHANGELOG.md)
- [Commits](https://github.com/paritytech/libsecp256k1/compare/v0.3.5...v0.7.0)
---
updated-dependencies:
- dependency-name: libsecp256k1
dependency-type: indirect
...
Signed-off-by: dependabot[bot] <[email protected]>