Cloudbuild updates: subset submodule update & bootstrap, remove build-all (project-chip#32753)

* Switch bootstrap and submodule checkouts to be restricted in cloudbuild

* Remove build-all: it was not running for a long time now and it compiles too much anyway at this point

* Update comment regarding silabs bootstrap

* Update the submodule checkout

* update checkout logic to be flatter

Author: andy31415

integrations/cloudbuild/build-all.yaml

@@ -5,14 +5,16 @@ steps:
           - "-c"
           - |
               git config --global --add safe.directory "*"
-              git submodule update --init --recursive
+              python scripts/checkout_submodules.py --shallow --recursive --platform esp32 nrfconnect silabs linux android 
       id: Submodules
     - name: "ghcr.io/project-chip/chip-build-vscode:41"
+      # NOTE: silabs boostrap is NOT done with the rest as it requests a conflicting
+      #       jinja2 version (asks for 3.1.3 when constraints.txt asks for 3.0.3)
       env:
           - PW_ENVIRONMENT_ROOT=/pwenv
       args:
           - "-c"
-          - source ./scripts/bootstrap.sh -p all,nrfconnect
+          - source ./scripts/bootstrap.sh -p all,esp32,nrfconnect,linux,android
       id: Bootstrap
       waitFor:
           - Submodules