ci(docs-infra): remove redundant standalone ngcc run (#36145)
ci(docs-infra): remove redundant standalone ngcc run (#36145)

Previously, in the `test_aio` CI job, we ran ngcc before building the
app with `yarn build`. This was supposed to have the benefit of taking
advantage of the parallel capabilities of standalone ngcc (vs implicitly
running it via `ng build`).

It turns out that the work done by the standalone ngcc was thrown away
before the `ng build`, resulting in `ng build` having to run ngcc all
over again. This happened because the `yarn build` script (run after the
standalone ngcc step) also runs `yarn install`, which essentially cleans
up `node_modules/`, thus discarding all the work already done by ngcc.

Here is an [example CI job][1], where this can be seen in action:
One can see the "Compiling <some-package> : es2015 as esm2015" logs in
the `yarn --cwd aio ngcc --properties es2015` step (as the standalone
ngcc processes the various entry-points) and then see the same logs in
the `yarn --cwd aio build --progress=false` step (as ngcc has to process
the entry-points all over again).

This commit removes the redundant standalone ngcc run and lets the CLI
handle ngcc via `ng build`. It is possible to instrument the build
process in a way that we can run the standalone ngcc after
`yarn install` and thus take advantage of the performance gains in
parallel mode, but the latest version of the CLI can already run ngcc in
parallel mode as a pre-build step, so this is unnecessary.

[1]: https://circleci.com/gh/angular/angular/658691

PR Close #36145

shairez/angular,ocombe/angular,angular-indonesia/angular,filipesilva/angular,blesh/angular,JiaLiPassion/angular,angular-indonesia/angular,shairez/angular,gdi2290/angular,JiaLiPassion/angular,gnomeontherun/angular,JiaLiPassion/angular,angular/angular,ocombe/angular,wKoza/angular,ocombe/angular,shairez/angular,ocombe/angular,filipesilva/angular,mgechev/angular,alxhub/angular,wKoza/angular,gdi2290/angular,angular/angular,ocombe/angular,alxhub/angular,filipesilva/angular,wKoza/angular,ocombe/angular,angular/angular,gnomeontherun/angular,filipesilva/angular,gdi2290/angular,gkalpak/angular,IdeaBlade/angular,manekinekko/angular,blesh/angular,shairez/angular,angular/angular,gnomeontherun/angular,blesh/angular,mgechev/angular,gdi2290/angular,alxhub/angular,brandonroberts/angular,brandonroberts/angular,gkalpak/angular,brandonroberts/angular,gkalpak/angular,manekinekko/angular,wKoza/angular,manekinekko/angular,brandonroberts/angular,shairez/angular,brandonroberts/angular,manekinekko/angular,gkalpak/angular,IdeaBlade/angular,blesh/angular,filipesilva/angular,IdeaBlade/angular,wKoza/angular,gnomeontherun/angular,gdi2290/angular,manekinekko/angular,manekinekko/angular,mgechev/angular,wKoza/angular,IdeaBlade/angular,brandonroberts/angular,angular-indonesia/angular,alxhub/angular,angular-indonesia/angular,blesh/angular,gdi2290/angular,JiaLiPassion/angular,IdeaBlade/angular,alxhub/angular,mgechev/angular,mgechev/angular