S3CSI-226: Port reconciler expectations system and CSI driver version label

[anurag4DSB]

Summary

• Port expectations system to prevent duplicate S3PodAttachment creation from reconciler races
• Add LabelCSIDriverVersion to S3PA for upgrade safety and pod sharing version checks

Changes

• cmd/scality-csi-controller/csicontroller/expectations.go: New expectations tracking
• cmd/scality-csi-controller/csicontroller/expectations_test.go: Unit tests for expectations
• cmd/scality-csi-controller/csicontroller/reconciler.go: Integrate expectations + version label
• cmd/scality-csi-controller/csicontroller/reconciler_test.go: Update for Requeue behavior

Test Plan

• Unit tests: setPending, isPending, clear, concurrent access, key derivation
• Reconciler test updated for new Requeue after S3PA creation
• GOOS=linux go vet passes
• CI E2E: Dynamic provisioning suite (30+ scenarios) exercises full reconciler path. Multi-volume suite exercises pod sharing with version label.

Issue: S3CSI-226

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.97%. Comparing base (75ee0ef) to head (9a2423b).
✅ All tests successful. No failed tests found.

Additional details and impacted files

see 1 file with indirect coverage changes

@@            Coverage Diff             @@
##             main     #325      +/-   ##
==========================================
+ Coverage   71.89%   71.97%   +0.07%     
==========================================
  Files          47       47              
  Lines        2669     2669              
==========================================
+ Hits         1919     1921       +2     
+ Misses        622      621       -1     
+ Partials      128      127       -1