[mlir][SparseTensor] Fix test regression

Fix a regression caused by https://reviews.llvm.org/D158012. Failing
bot:
  * https://lab.llvm.org/buildbot/#/builders/179/builds/7122

Note that both `RUN` lines in the affected file were previously
tested with similar configuraiton (_with_ and _without_ vectorisation).
This change restores that, though the new setting (from D158012) is
used, i.e.

  * with direct IR generation, `enable-runtime-library=true`.

This is sufficient to make the test pass and allows us to investigate
the root cause offline. Issue reported here:

  https://github.com/llvm/llvm-project/issues/64727