Update requirements.txt to include requests

[perfectra1n]

Currently as it is, the Docker container built from the Dockerfile exits with the following error:

Traceback (most recent call last):
  File "/usr/local/bin/vmware_exporter", line 5, in <module>
    from vmware_exporter.vmware_exporter import main
  File "/usr/local/lib/python3.7/site-packages/vmware_exporter/vmware_exporter.py", line 21, in <module>
    import requests
ModuleNotFoundError: No module named 'requests'

This PR includes requests in the requirements.txt file.

[easymoney322]

Still an issue

C:\Users\Administrator>vmware_exporter
Traceback (most recent call last):
  File "\\?\C:\Program Files\Python313\Scripts\vmware_exporter-script.py", line 33, in <module>
    sys.exit(load_entry_point('vmware-exporter==0.18.4', 'console_scripts', 'vmware_exporter')())
             ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "\\?\C:\Program Files\Python313\Scripts\vmware_exporter-script.py", line 25, in importlib_load_entry_point
    return next(matches).load()
           ~~~~~~~~~~~~~~~~~~^^
  File "C:\Program Files\Python313\Lib\importlib\metadata\__init__.py", line 179, in load
    module = import_module(match.group('module'))
  File "C:\Program Files\Python313\Lib\importlib\__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 1022, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "C:\Program Files\Python313\Lib\site-packages\vmware_exporter\vmware_exporter.py", line 21, in <module>
    import requests
ModuleNotFoundError: No module named 'requests'

PR is identical to the #345
However, the project isn't being maintained anymore, so I suggest forking or using otelcol.receiver.vcenter.

[perfectra1n]

Yeah I just moved to Proxmox anyways lol.