pybedtools.bedtool.BedTool.save_seqs leaves open .tmp files

[PeterRobots]

A warning is generated when using the command on a sequence.
Found when running unittests.

Python==3.8.0
async-timeout==4.0.2
attrs==22.2.0
biopython==1.79
certifi==2022.12.7
charset-normalizer==3.0.1
click==8.1.3
Cython==0.29.30
Deprecated==1.2.13
docker==5.0.3
exceptiongroup==1.1.0
Flask==2.2.2
idna==3.4
importlib-metadata==6.0.0
iniconfig==2.0.0
itsdangerous==2.1.2
Jinja2==3.1.2
MarkupSafe==2.1.2
mock==4.0.3
numpy==1.24.1
packaging==23.0
pkg_resources==0.0.0
pluggy==1.0.0
primer3-py==0.6.1
pybedtools==0.9.0
pycodestyle==2.9.1
pyfakefs==4.6.2
pysam==0.16.0.1
pytest==7.2.1
redis==4.3.3
requests==2.28.2
six==1.16.0
tomli==2.0.1
urllib3==1.26.14
websocket-client==1.4.2
Werkzeug==2.2.2
wrapt==1.14.1
zipp==3.11.0

It's resolved by closing self.seqfn after reading and writing to fout.