Add MemoryPressure alert

[ziccardi]

What

This pull request adds a MemoryPressure alert to the existing observability/monitoring configuration so that nodes under sustained memory pressure are detected and surfaced through our alerting pipeline.

Why

The new alert helps operators proactively identify clusters where memory consumption is close to critical levels, reducing the risk of node instability, OOM kills, and service degradation. By having an explicit MemoryPressure signal, we can react earlier, improve incident response, and maintain higher overall reliability of the platform.

Testing

Special notes for your reviewer

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[openshift-ci]

@ziccardi: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/cspr	5eb1e1d	link	true	/test cspr

Full PR test history. Your PR dashboard.

Details

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[ziccardi]

/test cspr

[ziccardi]

/retest-required

[ziccardi]

/retest

[roivaz]

/lgtm
/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: roivaz, ziccardi

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Details

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• dev-infrastructure/OWNERS [roivaz]
• observability/OWNERS [roivaz]

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