[tests] remove several empty oracles

tests/saveload/oracle/basic_sav.err

tests/saveload/oracle/bool_sav.err

tests/saveload/oracle/callbacks_sav.err

tests/saveload/oracle/deps_sav.err

tests/saveload/oracle/isset_sav.err

tests/saveload/oracle/multi_project_sav.err

tests/saveload/oracle/segfault_datatypes_sav.err

tests/saveload/oracle/sparecode_sav.err

tests/saveload/oracle/status_sav.err

tests/syntax/oracle/bool_conversion.err.oracle