refactor(cleanup): remove deprecated methods and properties (#8701)

`op` as a method on another operation was deprecated in 4.0.
`output_dtype` and `output_shape` were deprecated in 7.0.

I think 2 major versions is a reasonable deprecation cycle.

BREAKING CHANGE: Deprecated methods and properties `op`, `output_dtype`, and `output_shape` are removed. `op` is no longer needed, and use `.dtype` and `.shape` respectively for the other two.

ibis/expr/operations/core.py

@@ -9,7 +9,6 @@
 import ibis.expr.datashape as ds
 import ibis.expr.datatypes as dt
 import ibis.expr.rules as rlz
-from ibis import util
 from ibis.common.annotations import attribute
 from ibis.common.graph import Node as Traversable
 from ibis.common.grounds import Concrete
@@ -26,11 +25,6 @@ def equals(self, other) -> bool:
             )
         return self.__cached_equals__(other)
 
-    @util.deprecated(as_of="4.0", instead="remove intermediate .op() calls")
-    def op(self) -> Self:
-        """Make `Node` backwards compatible with code that uses `Expr.op()`."""
-        return self
-
     # Avoid custom repr for performance reasons
     __repr__ = object.__repr__
 
@@ -122,16 +116,6 @@ def relations(self):
         children = (n.relations for n in self.__children__ if isinstance(n, Value))
         return frozenset().union(*children)
 
-    @property
-    @util.deprecated(as_of="7.0", instead="use .dtype property instead")
-    def output_dtype(self):
-        return self.dtype
-
-    @property
-    @util.deprecated(as_of="7.0", instead="use .shape property instead")
-    def output_shape(self):
-        return self.shape
-
     def to_expr(self):
         import ibis.expr.types as ir