chore: deprecate REDUCE_DASHBOARD_BOOTSTRAP_PAYLOAD

[etr2460]

SUMMARY

This feature flag has been enabled by default for months now, let's remove it.

TEST PLAN

CI

ADDITIONAL INFORMATION

• Has associated issue:
• Changes UI
• Requires DB Migration.
• Confirm DB Migration upgrade and downgrade tested.
• Introduces new feature or API
• Removes existing feature or API

to: @ktmud @villebro @john-bodley

[etr2460]

i guess black likes this formatting better 🤷

[codecov-io]

Codecov Report

Merging #11244 into master will decrease coverage by 0.16%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master   #11244      +/-   ##
==========================================
- Coverage   65.61%   65.45%   -0.17%     
==========================================
  Files         832      832              
  Lines       39394    39394              
  Branches     3592     3592              
==========================================
- Hits        25848    25784      -64     
- Misses      13437    13501      +64     
  Partials      109      109              

Flag	Coverage Δ
#cypress	55.89% <ø> (-0.18%)	⬇️
#javascript	62.40% <ø> (ø)
#python	60.61% <100.00%> (-0.19%)	⬇️

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

Impacted Files	Coverage Δ
superset/views/core.py	74.11% <ø> (ø)
superset/config.py	90.07% <100.00%> (ø)
...rontend/src/visualizations/FilterBox/FilterBox.jsx	56.17% <0.00%> (-9.88%)	⬇️
superset/db_engine_specs/presto.py	73.65% <0.00%> (-8.43%)	⬇️
superset/examples/world_bank.py	97.10% <0.00%> (-2.90%)	⬇️
superset/examples/birth_names.py	97.36% <0.00%> (-2.64%)	⬇️
.../src/dashboard/components/gridComponents/Chart.jsx	83.67% <0.00%> (-2.05%)	⬇️
...set-frontend/src/dashboard/util/getDropPosition.js	90.47% <0.00%> (-1.59%)	⬇️
...t-frontend/src/dashboard/actions/dashboardState.js	50.32% <0.00%> (-1.31%)	⬇️
superset/models/core.py	88.12% <0.00%> (-0.28%)	⬇️
... and 3 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ae87b0c...d1dd53d. Read the comment docs.

[ktmud]

Merge to unblock #11234