chore(deps): update webpack

[hiroppy]

• This is a bugfix
• This is a feature
• This is a code refactor
• This is a test update
• This is a docs update
• This is a metadata update

For Bugs and Features; did you add new tests?

Motivation / Use-Case

webpack@4.39.1 cannot exit when a platform is Linux. Currently, all PRs are down so I add --forceExit flag to jest as temporary.

diff: webpack/webpack@v4.39.0...v4.39.1

closes: #2173

Breaking Changes

Additional Info

[codecov]

Codecov Report

Merging #2176 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2176   +/-   ##
=======================================
  Coverage   93.91%   93.91%           
=======================================
  Files          33       33           
  Lines        1265     1265           
  Branches      363      363           
=======================================
  Hits         1188     1188           
+ Misses         73       71    -2     
- Partials        4        6    +2

Impacted Files	Coverage Δ
client-src/clients/WebsocketClient.js	57.14% <0%> (ø)	⬆️

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