Support Pypy as interpreter

### Solution to issue cannot be found in the documentation.

- [X] I checked the documentation.

### Issue

I've installed Pypy as my python interpreter, and all the dependencies for xtensor-python (that are listed when I go to install it) have been installed okay when using pypy3 as the chosen interpreter in the environment.

I don't see any hard dependencies in the repo, but when I go to install xtensor-python, mamba is trying to uninstall my Pypy and replace it with CPython.

Is/should Pypy be supported as the interpreter here? Is there perhaps something wrong with my setup, or is this as expected?

Thanks

### Installed packages

```shell
(XTensorPythonTests-Pypy)
List of packages in environment: "/MicromambaRoot/envs/XTensorPythonTests-Pypy"

Name Version Build Channel
─────────────────────────────────────────────────────────────────
_libgcc_mutex 0.1 conda_forge conda-forge
_openmp_mutex 4.5 2_gnu conda-forge
bzip2 1.0.8 h7f98852_4 conda-forge
ca-certificates 2022.12.7 ha878542_0 conda-forge
expat 2.5.0 h27087fc_0 conda-forge
gdbm 1.18 h0a1914f_2 conda-forge
ld_impl_linux-64 2.39 hcc3a1bd_1 conda-forge
libblas 3.9.0 16_linux64_openblas conda-forge
libcblas 3.9.0 16_linux64_openblas conda-forge
libffi 3.4.2 h7f98852_5 conda-forge
libgcc-ng 12.2.0 h65d4601_19 conda-forge
libgfortran-ng 12.2.0 h69a702a_19 conda-forge
libgfortran5 12.2.0 h337968e_19 conda-forge
libgomp 12.2.0 h65d4601_19 conda-forge
liblapack 3.9.0 16_linux64_openblas conda-forge
libnsl 2.0.0 h7f98852_0 conda-forge
libopenblas 0.3.21 pthreads_h78a6416_3 conda-forge
libsqlite 3.40.0 h753d276_0 conda-forge
libstdcxx-ng 12.2.0 h46fd767_19 conda-forge
libuuid 2.32.1 h7f98852_1000 conda-forge
libzlib 1.2.13 h166bdaf_4 conda-forge
ncurses 6.3 h27087fc_1 conda-forge
numpy 1.24.1 py39hb10b683_0 conda-forge
openssl 3.0.7 h0b41bf4_1 conda-forge
pip 22.3.1 pyhd8ed1ab_0 conda-forge
pybind11 2.10.3 py39haa83c70_0 conda-forge
pybind11-global 2.10.3 py39haa83c70_0 conda-forge
pypy 7.3.9 0_pypy39 conda-forge
pypy3.9 7.3.9 hd671c94_7 conda-forge
python 3.9.12 0_73_pypy conda-forge
python_abi 3.9 3_pypy39_pp73 conda-forge
readline 8.1.2 h0f457ee_0 conda-forge
setuptools 66.1.1 pyhd8ed1ab_0 conda-forge
sqlite 3.40.0 h4ff8645_0 conda-forge
tk 8.6.12 h27826a3_0 conda-forge
tzdata 2022g h191b570_0 conda-forge
wheel 0.38.4 pyhd8ed1ab_0 conda-forge
xtensor 0.24.3 h924138e_1 conda-forge
xtl 0.7.5 hf52228f_0 conda-forge
xz 5.2.6 h166bdaf_0 conda-forge
zlib 1.2.13 h166bdaf_4 conda-forge
```

### Environment info

```shell
environment : XTensorPythonTests-Pypy (active)
env location : //MicromambaRoot/envs/XTensorPythonTests-Pypy
user config files : /home/user/.mambarc
populated config files : /home/user/.condarc
libmamba version : 1.1.0
micromamba version : 1.1.0
curl version : libcurl/7.87.0 OpenSSL/1.1.1s zlib/1.2.13 libssh2/1.10.0 nghttp2/1.47.0
libarchive version : libarchive 3.6.2 zlib/1.2.13 bz2lib/1.0.8 libzstd/1.5.2
virtual packages : __unix=0=0
__linux=5.15.0=0
__glibc=2.31=0
__archspec=1=x86_64
__cuda=11.6=0
channels :
base environment : /MicromambaRoot
platform : linux-64
```