[flang][runtime] Handle unconsumed repeated list-directed input items (#75400)

If list-directed input contains a repeated item ("20*123.0") that is not
fully consumed by the READ statement's data item list, the end of that
READ statement was repositioning the input to the repeated value
("123.0"), leading to later confusion. Cancel the input item repetition
during EndIoStatement() processing to prevent this misbehavior.

Fixes llvm-test-suite/Fortran/gfortran/regression/list_read_4.f90.