mbed deploy auto installs missing Python modules

I thought the auto-installation was already removed. But maybe this got forgotten

https://github.com/ARMmbed/mbed-cli/blob/1.10.2/mbed/mbed.py#L1697

You can accidentally ruin your python environment with following commands:
```
$ pip install mbed-cli==1.10.2
...
$ cd mbed-os-projext-X
...
$ mbed deploy
[mbed] Working path "/home/jaakor01/workspace/mbed-cloud-client-example" (program)
[mbed] Adding library "mbed-cloud-client" from "ssh://git@github.com/ARMmbed/mbed-cloud-client" at rev #a90cdc723466
[mbed] Adding library "mbed-os" from "ssh://git@github.com/ARMmbed/mbed-os" at rev #64853b354fa1
[mbed] Adding library "drivers/COMPONENT_WIFI_ISM43362" from "ssh://git@github.com/ARMmbed/wifi-ism43362" at rev #1c040113be0f
[mbed] Auto-installing missing Python modules (pyyaml, jsonschema, mbed_cloud_sdk, jinja2, mbed_ls, mbed_host_tests, mbed_greentea, pyelftools, manifest_tool, icetea, pycryptodome, pyusb, cmsis_pack_manager, psutil, cryptography, click)...
```