Per-component priorityClassName and update strategy; extend topologySpreadConstraints; remove unused hpa values

The airbyte-platform PR template directs contributions here, so filing this as an issue with a ready patch.

## Proposed change

Three small, related completions of the chart v2 scheduling surface:

1. `priorityClassName` for all workloads. Every component already exposes `nodeSelector`, `tolerations` and `affinity`; this adds the one standard scheduling field missing everywhere, in the identical guarded shape the existing `nodeSelector` blocks use.
2. `deploymentStrategyType` for the six components that currently hardcode their strategy (workload-launcher, connector-rollout-worker and metrics hardcode `Recreate`; featureflag-server, stigg-sidecar and workload-api-server hardcode `RollingUpdate`). Each new value defaults to the component's current literal, so nothing changes unless an operator opts in. This makes the strategy configurable; it does not change any default behavior.
3. `topologySpreadConstraints` for worker, workload-launcher and workload-api-server, extending the block airbyte-server already has.

Also removes the four `hpa: {enabled: false}` blocks in values.yaml that no template consumes; they read as a supported feature but render nothing.

## Why

Production self-managed clusters using preemption tiers and zone spreading currently cannot express either for most Airbyte components. The strategy knob matters for single-replica components on clusters where `Recreate` downtime windows are policy-relevant, while keeping the safe defaults for components where `Recreate` may be load-bearing.

## How

`priorityClassName` and `topologySpreadConstraints` reuse the existing passthrough patterns already used for `nodeSelector` and `affinity`. Every new value carries a `# --` helm-docs annotation. Renders with default values are unchanged. No changes to autogenerated files under templates/config.

A ready patch is available at https://github.com/airbytehq/airbyte-platform/compare/main...RafPe:airbyte-platform:chart-scheduling-disruption-surfaces; happy to open it as a PR wherever you prefer.

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**Internal Tracking:** https://github.com/airbytehq/oncall/issues/13246