Replace LALRPOP parser with hand-written parser

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_python_parser/resources/valid/statement/assignment.py

@@ -0,0 +1,40 @@
+x = (1, 2, 3)
+
+(x, y) = (1, 2, 3)
+
+[x, y] = (1, 2, 3)
+
+x.y = (1, 2, 3)
+
+x[y] = (1, 2, 3)
+
+(x, *y) = (1, 2, 3)
+
+
+# This last group of tests checks that assignments we expect to be parsed
+# (including some interesting ones) continue to be parsed successfully.
+
+*foo = 42
+
+[x, y, z] = [1, 2, 3]
+
+(x, y, z) = (1, 2, 3)
+x[0] = 42
+
+# This is actually a type error, not a syntax error. So check that it
+# doesn't fail parsing.
+
+5[0] = 42
+x[1:2] = [42]
+
+# This is actually a type error, not a syntax error. So check that it
+# doesn't fail parsing.
+5[1:2] = [42]
+
+foo.bar = 42
+
+# This is actually an attribute error, not a syntax error. So check that
+# it doesn't fail parsing.
+"foo".y = 42
+
+foo = 42