fix: deprecate migrate package

[anshumanv]

What kind of change does this PR introduce?
fix

Did you add tests for your changes?
NA

If relevant, did you update the documentation?
yep

Summary
deprecates migrate package as it's unusable now and doesn't handle webpack@5 and we can't cover all cases so it's advisable to follow migration guide, anyone who wishes to migrate to older versions can use the old published versions

Does this PR introduce a breaking change?
Not sure

Other information
/cc @alexander-akait

[codecov]

Codecov Report

Merging #2313 (51f5648) into master (8e7fbef) will increase coverage by 0.57%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2313      +/-   ##
==========================================
+ Coverage   67.48%   68.05%   +0.57%     
==========================================
  Files          64       52      -12     
  Lines        2519     2060     -459     
  Branches      589      508      -81     
==========================================
- Hits         1700     1402     -298     
+ Misses        819      658     -161     

Impacted Files	Coverage Δ
packages/utils/src/ast-utils.ts	8.26% <0.00%> (-17.77%)	⬇️
packages/utils/src/validate-identifier.ts	8.08% <0.00%> (-14.15%)	⬇️

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[rishabh3112]

I think we should update it for webpack@4 to webpack@5 using the migration guide https://webpack.js.org/migrate/5/.

[alexander-akait]

We don't have time and enough developers to do it, so I prefer not lose time on this

[alexander-akait]

And most of migrations are impossible to do due a lot of different cases

[alexander-akait]

The main idea - webpack migrate still will work for current version, but we remove this package from our code and will not update anymore

[anshumanv]

wip fixing conflicts

[anshumanv]

@alexander-akait fixed

[alexander-akait]

One fix and we can merge, I think we should remove this command from CLI docs page https://webpack.js.org/api/cli/, because now it is not rerecorded to use and deprecated

[anshumanv]

will make a PR on docs after release

[alexander-akait]

/cc @webpack/cli-team

[alexander-akait]

Feel free to merge when CI will be green

[alexander-akait]

And let's fix conflict

[alexander-akait]

Big thanks