You can fetch the package sources from fedora dist-git and you can build the packages locally using mock.
First you need to install the relevant mock config file from ./mock-configs in /etc/mock/
It's also recommended that you use fedpkg (which has a wrapper around mock) to do the builds since this simplifies the process.
# Clone the repo
fedpkg clone lld
cd lld
# Build the RPM Package
fedpkg mockbuild --root fedora-37-clang-15-x86_64
If you don't want to use fedpkg you can use plain mock instead.
# Clone the repo
git clone https://src.fedoraproject.org/rpms/lld.git
cd lld
# Download the sources
spectool -a -g lld.spec
# Build the SRPM
mock -r fedora-37-clang-15-x86_64 --buildsrpm --spec lld.spec --sources . --resultdir .
# Build the RPM package
mock -r fedora-37-clang-15-x86_64 --rebuild