>Much of MLIR requires compiling from source, from what I can tell
you can get apt packages from https://apt.llvm.org/ and build projects out of tree. you can also get packages from conda (https://github.com/conda-forge/mlir-feedstock). finally, if you look around on github you'll find tarred up releases too maintained by downstream users (e.g.https://github.com/ptillet/triton-llvm-releases).
you can also (as of very recently) build mlir-opt plugins just like for clang:
https://github.com/llvm/llvm-project/tree/main/mlir/examples...