Describe the bug

Some Exprs in DataFusion (mostly ScalarFunctions) are defined nullable but when being constant evaluated end up producing a (non-null) value. Since the replacement Expr::Literal is no longer nullable, this can in some cases lead to a schema change and trigger physical/logical schema mismatch check added in #11989

To Reproduce

Running the following query in datafusion cli

> SELECT combined FROM (
  SELECT concat('A', 'B') AS combined
  UNION ALL
  SELECT concat('A', 'B') AS combined
) GROUP BY combined;
Internal error: Physical input schema should be the same as the one converted from logical input schema..
This was likely caused by a bug in DataFusion's code and we would welcome that you file an bug report in our issue tracker

Expected behavior

The query should produce a result without errors.

Additional context

No response