[mlir][bazel] add alwayslink=True to mlir-runner utils

[j2kun]

MacOS platforms using mlir-runner in lit tests consistently hit the following error:

# .---command stderr------------
# | JIT session error: Symbols not found: [ __mlir_ciface_printMemrefI32 ]
# | Error: Failed to materialize symbols: { (main, { __mlir_printMemrefI32, ... }) }
# `-----------------------------

google/heir#1521 (comment) confirms the issue is fixed by using alwayslink on these two targets, and I confirmed on a separate Apple M1 (OSX version Sequoia 15.3.2.).

I'm not an expert on the mlir runner internals, but given the mlir-runner is purely for testing, and alwayslink at worst adds some overhead by not removing symbols, it seems low risk.