…al package detection (#35780)

Previously, `NgPackagesInstaller` would only look for Angular local
packages and do so by listing all (deeply nested) files in
`dist/packages-dist/` and looking for `package.json` files nested two
levels deep (i.e. `dist/packages-dist/*/package.json`). Thus, it would
unnecessarily check a large number of files.

This commit changes the package detection logic to instead look for
a `package.json` file directly inside each subdirectory of
`dist/packages-dist/`, which speeds up the operation.
It also refactors the code to make it easier to look for packages in
other directories (besides `dist/packages-dist/`). This will be useful
in a subsequent commit to look for and use the locally built `zone.js`
package (from `dist/zone.js-dist/`).

PR Close #35780

…local packages (#35780)

In some cases, we want to test the AIO app or docs examples against the
locally built Angular packages (for example to ensure that the changes
in a commit do not introduce a breaking change). In order to achieve
this, we have the `ng-packages-installer` script that handles updating
a project's `package.json` file to use the locally built Angular
packages (and appropriate versions for their (dev-/peer-)dependencies).

Previously, `ng-packages-installer` would only consider the locally
built Angular packages (from `dist/packages-dist/`). However, given that
Zone.js is now part of the `angular/angular` repo, it makes sense to
also use the locally built Zone.js package (from `dist/zone.js-dist/`).
Otherwise, the tests might fail for commits that update both the Angular
packages (and related docs examples) and the Zone.js package. An example
of such a simultaneous change (that would have broken tests) is #33838.

This commit updates the script to install the locally built Zone.js
package (in addition to the Angular ones). The commit ensures that the
Zone.js package will always be available alongside the Angular packages
(i.e. that the Zone.js package will be built by the same script that
builds the Angular packages and that the `dist/zone.js-dist/` directory
will be cached on CI).

Note: This problem was discovered while enabling docs examples unit
tests in #34374.

PR Close #35780

This commit moves the build-related scripts
(`build-ivy-npm-packages.js`, `build-packages-dist.js` and
`package-builder.js`) to a dedicated directory to keep the `scripts/`
directory cleaner.

It also moves the logic for building the `zone.js` package to a separate
script, `zone-js-builder.js`, to make it re-usable. A subsequent commit
will use it to build the `zone.js` package when building the Ivy Angular
packages as well.

PR Close #35780

…al package detection (#35780)

Previously, `NgPackagesInstaller` would only look for Angular local
packages and do so by listing all (deeply nested) files in
`dist/packages-dist/` and looking for `package.json` files nested two
levels deep (i.e. `dist/packages-dist/*/package.json`). Thus, it would
unnecessarily check a large number of files.

This commit changes the package detection logic to instead look for
a `package.json` file directly inside each subdirectory of
`dist/packages-dist/`, which speeds up the operation.
It also refactors the code to make it easier to look for packages in
other directories (besides `dist/packages-dist/`). This will be useful
in a subsequent commit to look for and use the locally built `zone.js`
package (from `dist/zone.js-dist/`).

PR Close #35780

…local packages (#35780)

In some cases, we want to test the AIO app or docs examples against the
locally built Angular packages (for example to ensure that the changes
in a commit do not introduce a breaking change). In order to achieve
this, we have the `ng-packages-installer` script that handles updating
a project's `package.json` file to use the locally built Angular
packages (and appropriate versions for their (dev-/peer-)dependencies).

Previously, `ng-packages-installer` would only consider the locally
built Angular packages (from `dist/packages-dist/`). However, given that
Zone.js is now part of the `angular/angular` repo, it makes sense to
also use the locally built Zone.js package (from `dist/zone.js-dist/`).
Otherwise, the tests might fail for commits that update both the Angular
packages (and related docs examples) and the Zone.js package. An example
of such a simultaneous change (that would have broken tests) is #33838.

This commit updates the script to install the locally built Zone.js
package (in addition to the Angular ones). The commit ensures that the
Zone.js package will always be available alongside the Angular packages
(i.e. that the Zone.js package will be built by the same script that
builds the Angular packages and that the `dist/zone.js-dist/` directory
will be cached on CI).

Note: This problem was discovered while enabling docs examples unit
tests in #34374.

PR Close #35780

…against local packages (angular#35780)"

This reverts commit 7d832ae; breaks CI
with error `Concurrent upstream jobs persisted the same file(s) into the workspace:`

…against local packages (#35780)" (#35857)

This reverts commit 7d832ae; breaks CI
with error `Concurrent upstream jobs persisted the same file(s) into the workspace:`

PR Close #35857

…against local packages (#35780)" (#35857)

This reverts commit 7d832ae; breaks CI
with error `Concurrent upstream jobs persisted the same file(s) into the workspace:`

PR Close #35857