Rollup merge of #126767 - compiler-errors:static-foreign-item, r=spastorino

`StaticForeignItem` and `StaticItem` are the same

The struct `StaticItem` and `StaticForeignItem` are the same, so remove `StaticForeignItem`. Having them be separate is unique to `static` items -- unlike `ForeignItemKind::{Fn,TyAlias}`, which use the normal AST item.

r? ``@spastorino`` or ``@oli-obk``

compiler/rustc_parse/src/parser/item.rs

@@ -1228,7 +1228,7 @@ impl<'a> Parser<'a> {
                                 ident_span: ident.span,
                                 const_span,
                             });
-                            ForeignItemKind::Static(Box::new(StaticForeignItem {
+                            ForeignItemKind::Static(Box::new(StaticItem {
                                 ty,
                                 mutability: Mutability::Not,
                                 expr,