chore: Upgrades Storybook to version 6.3.8 to make it compatible with Webpack 5

[michael-s-molina]

SUMMARY

#16701 migrated Webpack to version 5. This PR upgrades the Storybook to version 6.3.8 to make it compatible with the new Webpack version.

TESTING INSTRUCTIONS

• Open the Storybook
• All stories should be working

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 #16857 (946238c) into master (f703c12) will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #16857      +/-   ##
==========================================
+ Coverage   76.93%   76.97%   +0.03%     
==========================================
  Files        1021     1021              
  Lines       54708    54693      -15     
  Branches     7459     7457       -2     
==========================================
+ Hits        42092    42098       +6     
+ Misses      12372    12350      -22     
- Partials      244      245       +1     

Flag	Coverage Δ
javascript	71.19% <ø> (+0.06%)	⬆️

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

Impacted Files	Coverage Δ
...et-frontend/src/components/Select/NativeSelect.tsx	70.00% <0.00%> (-10.00%)	⬇️
...rontend/src/components/Select/DeprecatedSelect.tsx	80.39% <0.00%> (-1.97%)	⬇️
...d/src/explore/components/PropertiesModal/index.tsx	80.28% <0.00%> (-1.67%)	⬇️
...ols/FilterControl/AdhocFilterEditPopover/index.jsx	68.33% <0.00%> (-1.03%)	⬇️
...rset-frontend/src/explore/components/SaveModal.tsx	86.81% <0.00%> (-0.29%)	⬇️
...ponents/controls/TimeSeriesColumnControl/index.jsx	92.00% <0.00%> (+0.21%)	⬆️
...onfigModal/FiltersConfigForm/FiltersConfigForm.tsx	73.87% <0.00%> (+0.60%)	⬆️
...ols/DndColumnSelectControl/ColumnSelectPopover.tsx	16.12% <0.00%> (+0.97%)	⬆️
...trol/AdhocFilterEditPopoverSqlTabContent/index.jsx	62.50% <0.00%> (+1.20%)	⬆️
...ols/MetricControl/AdhocMetricEditPopover/index.jsx	83.46% <0.00%> (+3.31%)	⬆️
... and 1 more

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[villebro]

Thanks so much for fixing this, LGTM!