This is distilled from a larger example to be small/silly, however this caused real problems

A script which was intended for python3.6 exactly was written as follows:

```
#!/usr/bin/env python3.6
...
```

when creating a virtualenv with `python3.6 -m venv venv36` you end up with `python` / `python3` / `python3.6` executables in the venv

however, when creating a virtualenv with `python3 -m venv venv36` you only end up with `python` / `python3` executables

___

using `-mvirtualenv` (pypa/virtualenv) instead of venv, all three are reliably created

___

the fix is fairly straightforward, adding `f'python3.{sys.version_info[0]}'` to this tuple: https://github.com/python/cpython/blob/c33bdbb20cf55b3a2aa7a91bd3d91fcb59796fad/Lib/venv/__init__.py#L246