False positive ``unsubscriptable-object`` (#2307) (#2309)

Fix a regression in 2.15.7 for ``unsubscriptable-object``.

Raise an `InferenceError` when there is a `SyntaxError` due to an invalid `TypeVar` name.
This reverts commit 89dfb4857670a67920d0f3ab88857d697787901d.

Closes #2305
Closes pylint-dev/pylint#9069

(cherry picked from commit 1f0f2f8f780c3b639307a5f326b3963fdd6fa160)

Co-authored-by: Mark Byrne <31762852+mbyrnepr2@users.noreply.github.com>
3 files changed