cleanup: remove Mesos support from Falco.

[leogr]

What type of PR is this?

/kind cleanup

Any specific area of the project related to this PR?

/area engine

What this PR does / why we need it:

This follows up #2328 add deprecation warning for Mesos and completely removes the Mesos support from Falco.

/milestone 0.35.0

Does this PR introduce a user-facing change?:

update!: remove `--mesos-api`, `-pmesos`, and `-pm` command-line flags
BREAKING CHANGE: support for metadata enrichment from Mesos has been removed.

[FedeDP]

I noticed that we also have rules mentioning mesos: https://github.com/falcosecurity/rules/blob/main/rules/falco_rules.yaml#L1730
Are we going to clean them up too?

Btw thank you!
/approve

[leogr]

I noticed that we also have rules mentioning mesos: https://github.com/falcosecurity/rules/blob/main/rules/falco_rules.yaml#L1730 Are we going to clean them up too?

Btw thank you! /approve

I will take a look. Though, in that case, it seems to be legit (it refers to Mesos, the application, not our fields)

[jasondellaluce]

/approve

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: FedeDP, jasondellaluce, leogr

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