[pdl] Remove `NoSideEffect` from all PDL ops

This trait results in PDL ops being erroneously CSE'd. These ops are side-effect free in the rewriter but not in the matcher (where unused values aren't allowed anyways). These ops should have a more nuanced side-effect modeling, this is fixing a bug introduced by a previous change.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D120222