message: refactor(common): make `provideHttpClient` return `EnvironmentProviders`
  This commit updates the `provideHttpClient` function to return the `EnvironmentProviders` instead of a regular `Provider[]`, to make sure that the `provideHttpClient` can only be used where an environment is being setup.
  PR Close
diff: ```ts
  import { EnvironmentInjector } from '@angular/core';
  +import { EnvironmentProviders } from '@angular/core';
  import * as i0 from '@angular/core';
  import { InjectionToken } from '@angular/core';
  import { ModuleWithProviders } from '@angular/core';
  @@ -2162,7 +2163,7 @@ export class JsonpInterceptor {
  }
  // @public (undocumented)
  -export function provideHttpClient(...features: HttpFeature<HttpFeatureKind>[]): Provider[];
  +export function provideHttpClient(...features: HttpFeature<HttpFeatureKind>[]): EnvironmentProviders;
  // @public (undocumented)
  export function withInterceptors(interceptorFns: HttpInterceptorFn[]): HttpFeature<HttpFeatureKind.Interceptors>;
  