build: Convert utils, apm, angular, gatsby, ember to eslint

[AbhiPrasad]

• build: Switch @sentry/utils to using eslint
• build: Switch @sentry/apm to using eslint
• build: Switch @sentry/angular to using eslint
• build: Switch @sentry/gatsby to using eslint
• build: Switch @sentry/ember to using eslint (Basically already was using eslint)

Also updated so that lint would update cache - that should further reduce lint times (we can also store cache in github actions -> reduce CI time even more). It stores all the cache files in a top level folder called eslintcache.

Added some new rules:

// Prefer for-of loop over for loop if index is only used to access array
'@typescript-eslint/prefer-for-of': 'error',

// Make sure all expressions are used. Turned off in tests
// Must disable base rule to prevent false positives
'no-unused-expressions': 'off',
'@typescript-eslint/no-unused-expressions': 'error',

// Make sure Promises are handled appropriately
'@typescript-eslint/no-floating-promises': 'error',

// Do not use deprecated methods
'deprecation/deprecation': 'error',

What is left:

packages/integrations/**/*
packages/node/**/*
packages/react/**/*
packages/tracing/**/*
packages/typescript/**/*

[github-actions]

size-limit report

Path	Size
@sentry/browser - CDN Bundle (gzipped)	17.65 KB (-0.01% 🔽)
@sentry/browser - Webpack	18.41 KB (0%)
@sentry/react - Webpack	18.41 KB (0%)
@sentry/browser + @sentry/tracing - CDN Bundle (gzipped)	22.64 KB (-0.01% 🔽)

[getsentry-bot]

	Fails
🚫	Fatal error linting packages/ember/addon/index.ts with eslint.

	Warnings
⚠️	Please add a changelog entry for your changes.

	Messages
📖	@sentry/browser bundle gzip'ed minified size: (ES5: 17.249 kB) (ES6: 16.3477 kB)
📖	✅ TSLint passed

Generated by 🚫 dangerJS against cf4b5e6

[kamilogorek]

I went throught config files and they look good. As for the code part, if it lints, it lints ¯_(ツ)_/¯