[ROD]: Deploy v1.2.0 of Open VSX to production

### Production Pull Request (PR) Link

https://github.com/EclipseFdn/open-vsx.org/pull/13146

### Scope, Change Logs/Release Records

Changelog: https://github.com/eclipse-openvsx/openvsx/releases/tag/v1.2.0

Notable changes for our instance:

- enable trusted publishing
- add namespace ownership check
- set upper bound for fileresource cache to 2GB
- explicitly set server and webui urls

### Business Impact & Expected Downtime

Downtime expected (Requires active maintenance window)

### Requested Maintenance Window

September 29, 2026 10AM-4PM EST

### Functional Smoke Tests

TBD

### Pre & Post-Deployment Validation Checklist

- [ ] [PRE] Validate CDN caching hit ratios, bandwidth consumption, and SSL certificates binding
- [ ] [PRE] Verify EKS cluster health and readiness
- [ ] [PRE] Confirm application staging sign-off has been obtained
- [ ] [POST] Run functional smoke tests on all critical endpoints provided above
- [ ] [POST] Verify CDN cache hit ratio, bandwidth consumption and SSL certificate binding
- [ ] [POST] Monitor EKS pod restart rates and resource usage (CPU/Memory)
- [ ] [POST] Audit AWS, Fastly and Grafana dashboards for anomaly spikes

### Contingency Strategy Type

Hybrid / Complex Strategy (Detailed below)

Rollback involves database restoration

### Rollback / Roll-forward Plan & Thresholds

Rollback preferred

### 👉 [Dev Hand-off] Escalation Contacts

TBD

### SRE Operational Workflow Sign-off

- [ ] Consulted Product team and Service Delivery partners for explicit sign-off
- [ ] Confirmed, booked, and communicated the maintenance window broadly
- [ ] Executed end-to-end deployment process safely
- [ ] Validated all collaborative verification checklist items above
- [ ] Handed off to continuous monitoring (observing stability/escalating if needed)