Closes#5
Adds a Gitea Actions workflow that runs pre-commit checks and builds/tests the project on clang and gcc for both amd64 and arm64.
weaseljson is checked out, built, and installed locally because weaseldb depends on it via `find_package(weaseljson REQUIRED)`.
Also switches the llhttp FetchContent declaration from a tarball URL to a git repository pinned to the same release commit. The tarball redirect goes through codeload.github.com, which can be blocked in restricted network environments; using git keeps the fetch on github.com.
Reviewed-on: #6
Co-authored-by: Weaselbot <weaselbot@weaselab.dev>
Co-committed-by: Weaselbot <weaselbot@weaselab.dev>
