`benchopt install --env .` failure on this benchmark

```bash
(base) ➜ benchmark_logreg_l2 git:(main) benchopt install --env .
Installing 'benchmark_logreg_l2' requirements
Creating conda env 'benchopt_benchmark_logreg_l2':...

done
# Install
Collecting packages:
- 'Python-GD' already available in 'benchopt_benchmark_logreg_l2'
- 'Simulated' already available in 'benchopt_benchmark_logreg_l2'
... done
Installing required packages for:
- cd
- chop
- copt
- Lightning
- sklearn
- covtype_binary
- madelon
- news20
- rcv1
...Traceback (most recent call last):
File "/home/mathurin/anaconda3/bin/benchopt", line 33, in
sys.exit(load_entry_point('benchopt', 'console_scripts', 'benchopt')())
File "/home/mathurin/anaconda3/lib/python3.9/site-packages/click/core.py", line 1128, in __call__
return self.main(*args, **kwargs)
File "/home/mathurin/anaconda3/lib/python3.9/site-packages/click/core.py", line 1053, in main
rv = self.invoke(ctx)
File "/home/mathurin/anaconda3/lib/python3.9/site-packages/click/core.py", line 1659, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/mathurin/anaconda3/lib/python3.9/site-packages/click/core.py", line 1395, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/mathurin/anaconda3/lib/python3.9/site-packages/click/core.py", line 754, in invoke
return __callback(*args, **kwargs)
File "/home/mathurin/workspace/benchopt/benchopt/cli/main.py", line 274, in install
benchmark.install_all_requirements(
File "/home/mathurin/workspace/benchopt/benchopt/benchmark.py", line 233, in install_all_requirements
install_in_conda_env(
File "/home/mathurin/workspace/benchopt/benchopt/utils/conda_env_cmd.py", line 181, in install_in_conda_env
_run_shell_in_conda_env(
File "/home/mathurin/workspace/benchopt/benchopt/utils/shell_cmd.py", line 130, in _run_shell_in_conda_env
return _run_shell(
File "/home/mathurin/workspace/benchopt/benchopt/utils/shell_cmd.py", line 68, in _run_shell
raise RuntimeError(raise_on_error.format(output=output))
RuntimeError: Failed to conda install packages ('pip:https://github.com/openopt/copt/archive/master.zip', 'scikit-learn', 'pip:git+https://github.com/scikit-learn-contrib/lightning.git', 'pip:https://github.com/openopt/chop/archive/master.zip', 'numba', 'pip:scikit-learn', 'pip:libsvmdata')
Error:Collecting package metadata (current_repodata.json): ...working... done
Solving environment: ...working... failed with repodata from current_repodata.json, will retry with next repodata source.
Solving environment: ...working... failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): ...working... done
Solving environment: ...working... failed
Solving environment: ...working...
Building graph of deps: 0%| | 0/11 [00:00 numpy[version='1.13.*|>=1.10,<1.11.0a0|>=1.11.3,<2.0a0|>=1.16.6,<2.0a0|>=1.14.6,<2.0a0|>=1.9.3,<2.0a0|>=1.12,<1.13.0a0|>=1.14,<1.15.0a0|>=1.13,<1.14.0a0|>=1.11,<1.12.0a0']
- numba -> python[version='>=3.8,<3.9.0a0'] -> pip
- scikit-learn -> numpy[version='>=1.11.3,<2.0a0|>=1.14.6,<2.0a0|>=1.16.6,<2.0a0|>=1.9.3,<2.0a0']
- scikit-learn -> python[version='>=3.7,<3.8.0a0'] -> pip
- scikit-learn -> scipy[version='>=1.1.0'] -> numpy[version='>=1.15.1,<2.0a0']

The following specifications were found to be incompatible with each other:

Output in format: Requested package -> Available versions

Package python_abi conflicts for:
pip -> setuptools -> python_abi=3.8[build=*_cp38]
cython -> python_abi=3.8[build=*_cp38]
numba -> numpy[version='>=1.16.6,<2.0a0'] -> python_abi=3.8[build=*_cp38]
scikit-learn -> numpy[version='>=1.16.6,<2.0a0'] -> python_abi=3.8[build=*_cp38]
numpy -> python_abi=3.8[build=*_cp38]

Package setuptools conflicts for:
numba -> setuptools
scikit-learn -> joblib[version='>=0.11'] -> setuptools
pip -> setuptools
cython -> setuptools
python=3.8 -> pip -> setuptools

Package _libgcc_mutex conflicts for:
numpy -> libgcc-ng[version='>=7.5.0'] -> _libgcc_mutex[version='*|0.1|0.1',build='main|conda_forge']
cython -> libgcc-ng[version='>=7.5.0'] -> _libgcc_mutex[version='*|0.1|0.1',build='main|conda_forge']
python=3.8 -> libgcc-ng[version='>=7.5.0'] -> _libgcc_mutex[version='*|0.1|0.1',build='main|conda_forge']
numba -> _openmp_mutex[version='>=4.5'] -> _libgcc_mutex[version='*|0.1',build='main|conda_forge|main']
scikit-learn -> _openmp_mutex -> _libgcc_mutex[version='*|0.1',build='main|conda_forge|main']

Package libgfortran4 conflicts for:
scikit-learn -> scipy[version='>=1.1.0'] -> libgfortran4[version='>=7.5.0']
numpy -> libgfortran-ng[version='>=7,<8.0a0'] -> libgfortran4=7.5.0

Package pip conflicts for:
python=3.8 -> pip
cython -> python[version='>=3.8,<3.9.0a0'] -> pip
numpy -> python[version='>=3.8,<3.9.0a0'] -> pip

Package certifi conflicts for:
cython -> setuptools -> certifi[version='>=2016.09|>=2016.9.26']
pip -> setuptools -> certifi[version='>=2016.09|>=2016.9.26']
numba -> setuptools -> certifi[version='>=2016.09|>=2016.9.26']

Package libgomp conflicts for:
numba -> _openmp_mutex[version='>=4.5'] -> libgomp[version='>=7.5.0']
scikit-learn -> _openmp_mutex -> libgomp[version='>=7.5.0']

Package wheel conflicts for:
python=3.8 -> pip -> wheel
pip -> wheelThe following specifications were found to be incompatible with your system:

- feature:/linux-64::__glibc==2.31=0
- feature:|@/linux-64::__glibc==2.31=0
- cython -> libgcc-ng[version='>=7.5.0'] -> __glibc[version='>=2.17']
- numba -> libgcc-ng[version='>=7.5.0'] -> __glibc[version='>=2.17']
- numpy -> libgcc-ng[version='>=7.5.0'] -> __glibc[version='>=2.17']
- python=3.8 -> libgcc-ng[version='>=7.5.0'] -> __glibc[version='>=2.17']
- scikit-learn -> libgcc-ng[version='>=7.5.0'] -> __glibc[version='>=2.17']

Your installed version is: 2.31
```

Reproduce the failure with `benchopt install --env .` in the `benchmark_logreg_l2` environment. Trace the installation flow through `benchopt/cli/main.py`, `benchopt/benchmark.py`, `benchopt/utils/conda_env_cmd.py`, and `benchopt/utils/shell_cmd.py`, focusing on the reported conflicts among Python 3.8, NumPy, numba, and scikit-learn. Done means the benchmark requirements install successfully without the shown solver error.

Written by the indexing model from the issue text.