[chore][VERSIONING.md] Add long term support policy

[mx-psi]

Description

Adds support policy for Collector SIG software artifacts with the following principles:

• Support means that we will, at a minimum, fix critical bugs and security issues. We MAY fix other bugs and/or add features if needed (e.g. because a feature eases transition to a v2), but this is not required
• We support artifacts for end-users for longer
• Artifacts may contain sub-components that are not stable. The important bit is that users can easily tell when something is unstable.

Link to tracking issue

Fixes #10004

[mx-psi]

cc @open-telemetry/collector-approvers @open-telemetry/collector-contrib-approvers

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.28%. Comparing base (6029f31) to head (8205489).
Report is 36 commits behind head on main.

Additional details and impacted files

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##             main   #11001   +/-   ##
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  Coverage   92.28%   92.28%           
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  Files         413      413           
  Lines       19760    19760           
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  Hits        18236    18236           
  Misses       1152     1152           
  Partials      372      372           

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[songy23]

LGTM

[codeboten]

It would be good to have a section in this doc specifically defining what "supported" means

[codeboten]

When does support for a binary end?

[mx-psi]

It would be good to have a section in this doc specifically defining what "supported" means

The intention was that this sentence above:

critical bugs and security vulnerabilities MUST be addressed

was the definition of supported (or, at least, a minimum criteria for what supported means). We may do more than this, but that's the minimum.

When does support for a binary end?

This was also meant to be already covered in the text by this:

A binary distribution of the OpenTelemetry Collector MUST be supported for a minimum of one year after the release of the next major version of said distribution.

So, basically, we support the distro indefinitely until we release the next major version, after which we support it for one more year.

[mx-psi]

@codeboten if you think we should file an issue to continue discussing this please do so!

[atoulme]

I would add to this document a paragraph that explains that this policy is the current consensus, but it can change in the future, based on project direction and SIG discussions.

[tiffany76]

Just a few copy-edit suggestions.

[mx-psi]

I would add to this document a paragraph that explains that this policy is the current consensus, but it can change in the future, based on project direction and SIG discussions.

Done!

[mx-psi]

I'll merge this by end of week unless there are further comments, we can iterate on the wording and clarify support more but this feels like it is good enough for a first version given the number of approvals