upgraded docusaurus and fixed audit issues

[ihor-ki]

Changes

Fixing vulnerabilities:

1. Upgraded all Docusaurus packages in docs/ucx from ^3.7.0 to ^3.9.2 (@docusaurus/core, @docusaurus/preset-classic, @docusaurus/theme-mermaid, @docusaurus/module-type-aliases, @docusaurus/tsconfig, @docusaurus/types)
2. Added a resolutions field to docs/ucx/package.json to force serialize-javascript to >=7.0.3, fixing a transitive RCE vulnerability from webpack plugins
3. Regenerated yarn.lock

This resolves all 156 known yarn audit vulnerabilities (48 high, 81 moderate, 27 low) down to 0.

Linked issues

No issue

Functionality

• added relevant user documentation
• added new CLI command
• modified existing command: databricks labs ucx ...
• added a new workflow
• modified existing workflow: ...
• added a new table
• modified existing table: ...

Tests

• manually tested
• added unit tests
• added integration tests
• verified on staging environment (screenshot attached)

How to test

• run yarn audit (reports 0 vulnerabilities)
• run yarn build (completes successfully with no errors)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.77%. Comparing base (d7a1c55) to head (f546bee).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4733      +/-   ##
==========================================
- Coverage   87.95%   87.77%   -0.18%     
==========================================
  Files         123      123              
  Lines       17570    17569       -1     
  Branches     3714     3713       -1     
==========================================
- Hits        15453    15422      -31     
- Misses       1425     1458      +33     
+ Partials      692      689       -3     

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[github-actions]

❌ no tests were run

_{Running from acceptance #8975}