Explicitly declare optional peer deps in just-scripts

[Copilot]

• Add tryRequire() packages as optional peer deps
• Remove webpackCliInitTask and @webpack-cli/init dep
• Use ^ major ranges instead of >=
• Convert .syncpackrc.json to JS
• Rename .syncpackrc.js to syncpack.config.js
• Add resolve() packages as optional peer deps
• Update version ranges to match 2020-era major versions + all subsequent majors
• Install/upgrade optional peer dep packages as devDependencies of just-scripts
• Update tryRequire to take a generic type parameter <T>
• Update callsites to use tryRequire<typeof import('...')>(...)
• Enable esModuleInterop: true in root tsconfig.json
• Convert import * as X from 'cjs' → import X from 'cjs' where needed
• Convert import X = require('cjs') → import X from 'cjs'
• Fix type errors from upgraded packages (sass callback, webpack callback, etc.)
• Fix exec.spec.ts - use jest.mock for child_process with mock spy on spawn
• Restore nodeExecTask.test.ts and tscTask.spec.ts to use jest.mock / jest.spyOn
• Build, test, lint, format all pass
• Code review feedback addressed

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[ecraig12345]

@copilot

[ecraig12345]

@copilot

[ecraig12345]

1. You should also add any optional peer deps which are referenced with resolve()
2. For each optional peer dep, can you figure out what was the current version as of 2020 and update the range to allow that major version and all major versions after? Also reply to this comment with the list of major versions of each package and their release dates or if you're not able to determine this.

[Copilot]

Added all resolve() packages and updated ranges in 6ade4f5. Here's the version data for all optional peer deps:

Package	Latest as of 2020	Range
@microsoft/api-extractor	7.12.1 (2020-12-10)	^7.0.0
@microsoft/loader-load-themed-styles	1.9.21 (2020-12-14)	^1.0.0 || ^2.0.0
autoprefixer	10.1.0 (2020-12-08)	^10.0.0
css-loader	5.0.1 (2020-11-04)	^5.0.0 || ^6.0.0 || ^7.0.0
esbuild	0.8.28 (2020-12-31)	>=0.8.0 (never had v1)
eslint	7.16.0 (2020-12-18)	^7.0.0 || ^8.0.0 || ^9.0.0 || ^10.0.0
fork-ts-checker-webpack-plugin	6.0.8 (2020-12-20)	^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0
html-webpack-plugin	4.5.0 (2020-09-21)	^4.0.0 || ^5.0.0
jest	26.6.3 (2020-11-04)	^26.0.0 || ^27.0.0 || ^28.0.0 || ^29.0.0 || ^30.0.0
node-sass	5.0.0 (2020-10-31)	^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0
postcss	8.2.2 (2020-12-29)	^8.0.0
postcss-clean	1.1.0 (2017-09-15)	^1.0.0
postcss-loader	4.1.0 (2020-11-19)	^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0
postcss-rtl	1.7.3 (2020-03-11)	^1.0.0 || ^2.0.0
prettier	2.2.1 (2020-11-28)	^2.0.0 || ^3.0.0
sass	1.32.0 (2020-12-30)	^1.0.0
sass-loader	10.1.0 (2020-11-11)	^10.0.0 || ^11.0.0 || ^12.0.0 || ^13.0.0 || ^14.0.0 || ^15.0.0 || ^16.0.0
style-loader	2.0.0 (2020-10-09)	^2.0.0 || ^3.0.0 || ^4.0.0
tar-fs	2.1.1 (2020-11-06)	^2.0.0 || ^3.0.0
tslint	6.1.3 (2020-07-31)	^6.0.0 (deprecated)
tslint-microsoft-contrib	6.2.0 (2019-05-24)	^6.0.0 (deprecated)
typescript	4.1.3 (2020-12-11)	^4.0.0 || ^5.0.0 || ^6.0.0
webpack	5.11.1 (2020-12-28)	^4.0.0 || ^5.0.0
webpack-cli	4.3.1 (2020-12-31)	^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0
webpack-dev-server	3.11.1 (2020-12-29)	^3.0.0 || ^4.0.0 || ^5.0.0