fix(executor): honor the negate flag on LIKE and ILIKE [CLAUDE]

[jbylund]

The bug

x NOT LIKE 'p' parses as a single exp.Like carrying negate=True, not an exp.Not wrapping an exp.Like. Neither Like nor ILike was in PythonGenerator.TRANSFORMS, so both fell through to _rename, which does not read the flag. LIKE and NOT LIKE generated byte-identical code:

a NOT LIKE 'p'     ->  LIKE(scope[None]["a"], 'p')
a LIKE 'p'         ->  LIKE(scope[None]["a"], 'p')

so the predicate returned exactly the rows the query asked to exclude:

>>> from sqlglot.executor import execute
>>> t = {"t": [{"s": "Bump version"}, {"s": "Add feature"}]}
>>> execute("SELECT s FROM t WHERE s NOT LIKE 'Bump%'", tables=t).rows
[('Bump version',)]      # every row it excluded, and none it asked for

No exception -- a full result that is quietly the inverse of the query. Spelling it NOT (x LIKE 'p') has always worked, which is what makes it easy to miss.

The fix

exp.Is already reads negate in TRANSFORMS, and Is/Like/ILike are the only three nodes whose arg_types carry the flag -- so this completes the set.

The negation is routed through NOT rather than inverting in Python, so the generated code is exactly what the NOT (x LIKE 'p') spelling already produces and the three-valued logic comes from the same SQL_NOT. A NULL operand therefore matches neither form, which the test asserts.

Note, out of scope

ILIKE is separately absent from the executor's ENV, so both ILIKE and NOT ILIKE still raise name 'ILIKE' is not defined. That is a different gap -- this change means the flag will be honored once it is filled.

Tests

test_negated_like asserts NOT LIKE returns the complement and agrees exactly with NOT (x LIKE ...), NULL row included. test_py_dialect gains the two codegen assertions.

Full suite passes: SKIP_INTEGRATION=1 python -m unittest -> 1314 tests, OK.