sysutils/py-croniter: Fix shebang

> Running Q/A tests (stage-qa)

Error: '/usr/bin/env python' is an invalid shebang you need USES=shebangfix for 'lib/python3.11/site-packages/croniter/tests/test_croniter_speed.py'
Error: '/usr/bin/env python' is an invalid shebang you need USES=shebangfix for 'lib/python3.11/site-packages/croniter/tests/test_croniter_range.py'
Error: '/usr/bin/env python' is an invalid shebang you need USES=shebangfix for 'lib/python3.11/site-packages/croniter/tests/test_croniter.py'
Error: '/usr/bin/env python' is an invalid shebang you need USES=shebangfix for 'lib/python3.11/site-packages/croniter/tests/test_croniter_dst_repetition.py'

• Error code 1

Approved by: portmgr (blanket)