Add startup probes and relax probe timings for CI stability

[efiacor]

Description

• What changed: Added startupProbe to porch-server, porch-controllers, and function-runner. Increased readiness probe failureThreshold and periodSeconds. Added missing livenessProbe to function-runner.
• Why it's needed: CI flakiness from pods being killed during slow startup when using kpt live apply.
• How it works: Startup probes gate liveness/readiness checks, giving containers up to ~155s to initialize before any kill decisions are made.

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Related Issue(s)

• N/A (CI flakiness observed in deploy pipeline)

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Type of Change

• Bug fix
• Enhancement

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Checklist

• Code follows project style guidelines
• Self-reviewed changes
• Tests added/updated
• Documentation added/updated
• All tests and gating checks pass

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Testing Instructions (Optional)

1. Deploy to kind cluster with make run-in-kind-v1alpha2
2. Observe pods start without probe-related restarts
3. Run e2e tests to confirm no regressions

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Additional Notes (Optional)

• Postgres probes were already well-configured (startup probe with 300s budget) — left unchanged
• .build/deploy/ copies also updated locally but are gitignored

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AI Disclosure

• I have used AI in the creation of this PR.

If so, please describe how:

• Kiro to analyse existing probe configurations and generate relaxed timings with startup probes.
• The author has fully verified all code.