Request - CI warning when changing existing metrics names

### Use Case

As requested, split of #18919 => bonus

Related to the very recent changes for the inputs.system modules altering some long lasting metric names,
would it be possible to implement a warning in the CI against the change of existing metrics name, to remind about the impact ?
Many of them exist since years, while the change in the code might be trivial, the impact for the users is not.

At first glance, I'm not seeing a simple way for that, but maybe someone has an idea.
Maybe comparing a protected list for each module, which should have only new lines when updated, raising a informational warning, or requiring a bypass after being acknowledged.

This would be to ensure keeping the stability between versions and reducing undesired metric renaming or removal.

Thanks.

### Expected behavior

-

### Actual behavior

-

### Additional info

_No response_

Start by reviewing the related changes in #18919 and the inputs.system modules whose metric names were altered. Determine how CI could detect renamed or removed existing metrics and define what warning, acknowledgement, or bypass should count as done.

Written by the indexing model from the issue text.