chore(deps): Update dependencies

npm-check-updates output:

 @angular-builders/custom-webpack    ^14.0.0  →    ^15.0.0
 @angular-devkit/build-angular       ^14.0.2  →    ^15.1.4
 @angular/animations                 ^14.0.3  →    ^15.1.2
 @angular/cli                        ^14.0.2  →    ^15.1.4
 @angular/common                     ^14.0.3  →    ^15.1.2
 @angular/compiler                   ^14.0.3  →    ^15.1.2
 @angular/compiler-cli               ^14.0.3  →    ^15.1.2
 @angular/core                       ^14.0.3  →    ^15.1.2
 @angular/forms                      ^14.0.3  →    ^15.1.2
 @angular/platform-browser           ^14.0.3  →    ^15.1.2
 @angular/platform-browser-dynamic   ^14.0.3  →    ^15.1.2
 @angular/router                     ^14.0.3  →    ^15.1.2
 @types/node                        ^12.11.1  →  ^18.11.18
 dotenv                              ^16.0.1  →    ^16.0.3
 rxjs                                 ~6.6.0  →     ~7.8.0
 tslib                                ^2.0.0  →     ^2.5.0
 typescript                           ~4.6.4  →     ~4.9.5
 webpack                             ^5.67.0  →    ^5.75.0
 zone.js                             ~0.11.4  →    ~0.12.0

Major changes

most of changes are regarding new v15 angular release (dropping support for lower versions of node and typescript and other changes in angular)
- overview of changes v15 (breaking changes)
@angular-builders/custom-webpack
@angular-devkit/build-angular
- breaking changes
@angular/animations, @angular/cli, @angular/common, @angular/compiler, @angular/compiler-cli, @angular/core, @angular/forms, @angular/platform-browser, @angular/platform-browser-dynamic, @angular/router
- breaking changes
@types/node - multiple changes from v12 to v18 in native packages (crypto, process, http, tls, worker-threads, …)
rxjs - splitting packages, schedulers, typescript version support

`npm audit`

on main branch found 6 vulnerabilities (1 low, 1 moderate, 3 high, 1 critical)
after npm audit fix found 3 high severity vulnerabilities
after update of dependencies listed above found 0 vulnerabilities

ButterCMS / angular-starter-buttercms

chore(deps): Update dependencies #19

Major changes

`npm audit`