Re-Enable `-fdefer-type-errors` and `-fdefer-out-of-scope-variables` in GHCi

Summary

GHCi has -fdefer-type-errors and -fdefer-out-of-scope-variables was disabled as an adhoc fix to avoid some serious issue #14963 (closed). Now that the real issue is fixed by we should re-enable -fdefer-type-errors and -fdefer-out-of-scope-variables in GHCi.

More info: #14963 (comment 546391)

Steps to reproduce

Check #14963 (closed)

Expected behavior

Code snippet in #14963 (closed) shouldn't crash

Environment

• GHC version used: HEAD