chore(security): Remove obsolete FAB metric_access permission

[john-bodley]

SUMMARY

Per here the metric_access permission is obsolete and not used anywhere.

Note I assume that FAB should clean up after itself and thus no explicit migration is necessary.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

CI.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #16860 (fd314b7) into master (51090c3) will increase coverage by 2.56%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #16860      +/-   ##
==========================================
+ Coverage   66.35%   68.91%   +2.56%     
==========================================
  Files        1569     1613      +44     
  Lines       61692    69565    +7873     
  Branches     6240     6240              
==========================================
+ Hits        40934    47943    +7009     
- Misses      19161    20025     +864     
  Partials     1597     1597              

Flag	Coverage Δ
hive	54.30% <ø> (+1.06%)	⬆️
mysql	83.48% <ø> (+1.39%)	⬆️
postgres	83.54% <ø> (+1.39%)	⬆️
presto	54.25% <ø> (+1.17%)	⬆️
python	83.92% <ø> (+1.33%)	⬆️
sqlite	83.27% <ø> (+1.43%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
superset/security/manager.py	94.39% <ø> (+2.43%)	⬆️
superset/commands/importers/v1/examples.py	29.31% <0.00%> (-9.33%)	⬇️
superset/security/api.py	96.96% <0.00%> (-3.04%)	⬇️
superset/dataframe.py	88.88% <0.00%> (-2.78%)	⬇️
superset/reports/notifications/slack.py	85.43% <0.00%> (-1.89%)	⬇️
superset/charts/post_processing.py	67.14% <0.00%> (-1.07%)	⬇️
superset/datasets/schemas.py	96.15% <0.00%> (-0.89%)	⬇️
superset/examples/bart_lines.py	25.00% <0.00%> (-0.81%)	⬇️
superset/common/query_context_processor.py	90.69% <0.00%> (-0.69%)	⬇️
superset/db_engine_specs/teradata.py	89.47% <0.00%> (-0.53%)	⬇️
... and 113 more

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[villebro]

🔥

[dpgaspar]

@john-bodley this is a custom Superset permission and not a FAB one, FAB will only cleanup registered Flask methods on BaseViews, it will not manage unknown permissions that exist on the DB. So on this case would be nice to add a migration to cleanup