Fix uncaught permission exception in VertexAIFeatureStoreEnrichmentHandler

[vishalmore90]

fixes #40442

Context

VertexAIFeatureStoreEnrichmentHandler is designed to log a warning and proceed if the user lacks sufficient admin permissions to verify the feature store's existence during initialization. However, the get_feature_online_store RPC call—which actually performs the permission check—was placed in the else block of the try...except Exception structure. This caused PermissionDenied errors to bypass the intended fallback and crash the pipeline.

Changes

Moved get_feature_online_store and its path resolution methods out of the else block and into the try block. This correctly catches exceptions (e.g., PermissionDenied) thrown during the RPC call and triggers the intended _LOGGER.warning fallback.

Verification

• Manually inspected the try...except control flow.
• Verified Python syntax via py_compile.
• Relies on existing GitHub Actions Python Tests workflows to ensure no regressions in enrichment handler unit tests.

Checklist

• Mention the appropriate issue in your description (for example: addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, comment fixes #<ISSUE NUMBER> instead.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

[github-actions]

Assigning reviewers:

R: @shunping for label python.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.20%. Comparing base (7203268) to head (3fdc81c).
⚠️ Report is 122 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #40443      +/-   ##
============================================
+ Coverage     56.14%   56.20%   +0.06%     
  Complexity     2288     2288              
============================================
  Files          1121     1123       +2     
  Lines        177151   178189    +1038     
  Branches       1488     1488              
============================================
+ Hits          99466   100157     +691     
- Misses        75161    75508     +347     
  Partials       2524     2524              

Flag	Coverage Δ
python	79.67% <100.00%> (-0.17%)	⬇️

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