[Feature Request] pyenv install should recognize version in pyenv-virtualenv format

[loynoir]

Example

$ cat .python-version
3.9.9/envs/foobar

Actual

$ cat .python-version
3.9.9/envs/foobar

$ pyenv install
python-build: definition not found: 3.9.9/envs/foobar

See all available versions with `pyenv install --list'.

If the version you need is missing, try upgrading pyenv.

Expected

$ cat .python-version
3.9.9/envs/foobar

$ pyenv virtualenvs | grep -F 3.9.9/envs/foobar  || echo OK
OK
$ pyenv install
$ pyenv virtualenvs | grep -F 3.9.9/envs/foobar
3.9.9/envs/foobar (created from ~/.pyenv/versions/3.9.9)