[Bug] requirements.txt uses static version of ansible-core

[lm-sig]

Describe the bug
The requirements file as of version 2.0.0 points to a single version of ansible-core.

ansible-core==2.15.0

The README says "This collection requires ansible-core>=2.15.0" so which is it?

Ideally the requirements.txt file should match the README. As it is configured today the static assignment breaks some use cases. I use the requirements.txt with pip install (pip install -r ./requirements.txt). With Ansible 9 or Ansible 10 (ansible-core 2.16.x / ansible-core 2.17.x) the pip install tries to downgrade ansible-core to meet the nutanix.ncp requirements.txt file.

To Reproduce
Steps to reproduce the behavior:

1. pip install ansible==10.7.0
2. pip install -r ./nutanix/ncp/requirements.txt

Stack trace

...
  Attempting uninstall: ansible-core
    Found existing installation: ansible-core 2.17.7
    Uninstalling ansible-core-2.17.7:
      Successfully uninstalled ansible-core-2.17.7
...

Expected behavior
Ansible-core 2.16.x or higher should not be uninstalled and downgraded to 2.15.x.

Additional context

[lm-sig]

I'm not sure if the requirements.txt file is the best place for this, IMHO. Ansible already has a mechanism to check the ansible-core requirement in meta/runtime.yml and you are already using that. Other collections do not include ansible-core in their requirements.txt file so maybe it should just be removed.