devel/libgit2: Update to 0.99.0
- Switch to the release tarballs libgit2 now publishes
- Drop CURL option since it is no longer used
- Use system libpcre instead of the bundled one
- Hook up tests
- Bump consumers for ABI changes
Changes: https://github.com/libgit2/libgit2/releases/tag/v0.99.0
ABI: https://abi-laboratory.pro/tracker/timeline/libgit2/