Completely disable outside python

```julia
Package Version Build Channel Size
───────────────────────────────────────────────────────────────────────
Reinstall:
───────────────────────────────────────────────────────────────────────

o libstdcxx-ng 11.3.0 h239ccf8_18 conda-forge Cached
o python 3.10.6 h582c2e5_0_cpython conda-forge Cached

Summary:

Reinstall: 1 packages

Total download: 0 B

───────────────────────────────────────────────────────────────────────

Transaction starting
Changing libstdcxx-ng-11.3.0-h239ccf8_18 ==> libstdcxx-ng-11.3.0-h239ccf8_18
Changing python-3.10.6-h582c2e5_0_cpython ==> python-3.10.6-h582c2e5_0_cpython
Transaction finished
Python path configuration:
PYTHONHOME = '/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt'
PYTHONPATH = '/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib/python3.9/site-packages/itk:/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/python:/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib:/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib/python3.9/site-packages'
program name = '/home/jiling/.julia/dev/WVZAnalysis/.CondaPkg/env/bin/python'
isolated = 0
environment = 1
user site = 1
import site = 1
sys._base_executable = '/home/jiling/.julia/dev/WVZAnalysis/.CondaPkg/env/bin/python'
sys.base_prefix = '/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt'
sys.base_exec_prefix = '/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt'
sys.platlibdir = 'lib'
sys.executable = '/home/jiling/.julia/dev/WVZAnalysis/.CondaPkg/env/bin/python'
sys.prefix = '/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt'
sys.exec_prefix = '/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt'
sys.path = [
'/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib/python3.9/site-packages/itk',
'/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/python',
'/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib',
'/cvmfs/sft-nightlies.cern.ch/lcg/views/dev4/Wed/x86_64-centos7-gcc11-opt/lib/python3.9/site-packages',
'/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt/lib/python310.zip',
'/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt/lib/python3.10',
'/cvmfs/sft.cern.ch/lcg/releases/Python/3.9.12-9a1bc/x86_64-centos7-gcc11-opt/lib/python3.10/lib-dynload',
]
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
```

The outside environment setup a pretty intrusive set of environment variables, how to protect against it?