Match @angular 12 libraries to allow rxjs upgrade to v7.x

[jasonkenneth]

I'm submitting a ...

[x] bug report => Search github for a similar issue or PR before submitting
[ ] feature request => Please check if request is not on the roadmap already https://github.com/primefaces/primeng/wiki/Roadmap
[ ] support request => Please do not submit support request here, instead see http://forum.primefaces.org/viewforum.php?f=35

Plunkr Case (Bug Reports)
https://stackblitz.com/edit/github-2938vs?file=package.json
(Download and run npm install)

Description

Even though Angular 12 shipped with rxjs v6, they made changes to support v7.

angular/angular#41897
angular/angular#42991
https://github.com/angular/angular/blob/12.2.12/packages/core/package.json#L14

Current behavior
Get an error when running npm install. When running npm install in an Angular 12 project with rxjs v7x, we get the following error.

From our app:

npm ERR! Found: rxjs@7.4.0
npm ERR! node_modules/rxjs
npm ERR!   rxjs@"7.4.0" from the root project
npm ERR!   peer rxjs@"^6.5.3 || ^7.0.0" from @angular/common@12.2.12
npm ERR!   node_modules/@angular/common
npm ERR!     @angular/common@"12.2.12" from the root project
npm ERR!     peer @angular/common@"^7.0.0 || ^8.0.0 || ^9.0.0 || ^10.0.0 || ^11.0.0 || ^12.0.0" from primeng@12.2.1
npm ERR!     node_modules/primeng
npm ERR!       primeng@"12.2.1" from the root project
npm ERR!     2 more (@angular/forms, @angular/platform-browser)
npm ERR!   2 more (@angular/core, @angular/forms)
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer rxjs@"^6.0.0" from primeng@12.2.1
npm ERR! node_modules/primeng
npm ERR!   primeng@"12.2.1" from the root project

From stackblitz:

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: xorijgwpj.github@0.0.0
npm ERR! Found: rxjs@7.4.0
npm ERR! node_modules/rxjs
npm ERR!   rxjs@"^7.4.0" from the root project
npm ERR!   peer rxjs@"^6.5.3 || ^7.0.0" from @angular/common@12.2.12
npm ERR!   node_modules/@angular/common
npm ERR!     @angular/common@"12.2.12" from the root project
npm ERR!     peer @angular/common@"^7.0.0 || ^8.0.0 || ^9.0.0 || ^10.0.0 || ^11.0.0 || ^12.0.0" from primeng@12.1.1
npm ERR!     node_modules/primeng
npm ERR!       primeng@"12.1.1" from the root project
npm ERR!     2 more (@angular/forms, @angular/platform-browser)
npm ERR!   2 more (@angular/core, @angular/forms)
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer rxjs@"^6.0.0" from primeng@12.1.1
npm ERR! node_modules/primeng
npm ERR!   primeng@"12.1.1" from the root project

Expected behavior
npm install should work without any errors

Minimal reproduction of the problem with instructions

1. Start an angular 12 project
2. Reference primeng@12.2.1
3. Set rxjs version to 7.4.0
4. Run npm install

What is the motivation / use case for changing the behavior?
Allow use of upgraded rxjs without using the --force option on npm install.

Please tell us about your environment:
Linux, npm@latest-7

• Angular version: 12.2.2

• PrimeNG version: 12.2.1

• Browser: N/A

• Language: TypeScript 4.4

• Node (for AoT issues): node --version = v14.16.1