Auto merge of #134248 - oli-obk:patkind-path-removal, r=BoxyUwU

Merge `PatKind::Path` into `PatKind::Expr`

Follow-up to #134228

We always had a duplication where `Path`s could be represented as `PatKind::Path` or `PatKind::Lit(ExprKind::Path)`. We had to handle both everywhere, and still do after #134228, so I'm removing it now.

Author: bors