ci: move the `test_saucelabs_bazel` CircleCI job to `default_workflow` (#31636)
ci: move the `test_saucelabs_bazel` CircleCI job to `default_workflow` (#31636)

Previously, the `test_saucelabs_bazel` job was run as part of the
`saucelabs_test` workflow every hour (for every "publish branch";
currently 8.0.x, 8.1.x and master).

Since this job runs a subset of the tests in
`legacy-unit-tests-saucelabs` (see [BUILD.bazel][1]) and is just a
proof-of-concept for running tests on SauceLabs via bazel, there is
little point in running is on all branches. It is also wasteful to run
it every hour, even if there were no changes pushed into the branch
since the last run.

This commit makes the job part of `default_workflow`, but limits it to
only be run on master builds (not on other branches or PRs). Based on
its recent history, the job is relatively stable and (since it will only
be run on master builds) it is not expected to affect our dev workflow.

[1]: https://github.com/angular/angular/blob/ef44f51d5/BUILD.bazel#L66-L92

PR Close #31636

manekinekko/angular,Brocco/angular,mgechev/angular,alxhub/angular,IdeaBlade/angular,alexeagle/angular,matsko/angular,StephenFluin/angular,filipesilva/angular,shairez/angular,matsko/angular,vikerman/angular,alexeagle/angular,blesh/angular,snaptech/angular,vikerman/angular,angular-indonesia/angular,ocombe/angular,alxhub/angular,ocombe/angular,brandonroberts/angular,vikerman/angular,ocombe/angular,wKoza/angular,mprobst/angular,mhevery/angular,brandonroberts/angular,matsko/angular,filipesilva/angular,angular-indonesia/angular,angular-indonesia/angular,sarunint/angular,gdi2290/angular,gnomeontherun/angular,manekinekko/angular,JiaLiPassion/angular,Toxicable/angular,gnomeontherun/angular,alexeagle/angular,JiaLiPassion/angular,shairez/angular,JiaLiPassion/angular,manekinekko/angular,Toxicable/angular,gdi2290/angular,angular/angular,alexeagle/angular,blesh/angular,wKoza/angular,gnomeontherun/angular,gkalpak/angular,alxhub/angular,alxhub/angular,blesh/angular,angular/angular,IdeaBlade/angular,Brocco/angular,brandonroberts/angular,brandonroberts/angular,gkalpak/angular,mgechev/angular,filipesilva/angular,gnomeontherun/angular,manekinekko/angular,StephenFluin/angular,Brocco/angular,manekinekko/angular,gdi2290/angular,StephenFluin/angular,StephenFluin/angular,snaptech/angular,angular-indonesia/angular,IdeaBlade/angular,alexeagle/angular,ocombe/angular,Toxicable/angular,alexeagle/angular,Brocco/angular,wKoza/angular,mgechev/angular,ocombe/angular,alxhub/angular,gkalpak/angular,mprobst/angular,vikerman/angular,angular/angular,mhevery/angular,mgechev/angular,Brocco/angular,mprobst/angular,Toxicable/angular,snaptech/angular,sarunint/angular,shairez/angular,blesh/angular,ocombe/angular,IdeaBlade/angular,filipesilva/angular,manekinekko/angular,gdi2290/angular,snaptech/angular,snaptech/angular,mhevery/angular,matsko/angular,blesh/angular,gkalpak/angular,vikerman/angular,mhevery/angular,wKoza/angular,wKoza/angular,snaptech/angular,Toxicable/angular,Toxicable/angular,StephenFluin/angular,filipesilva/angular,gdi2290/angular,vikerman/angular,mhevery/angular,brandonroberts/angular,Brocco/angular,sarunint/angular,mprobst/angular,shairez/angular,IdeaBlade/angular,angular/angular,sarunint/angular,sarunint/angular,mprobst/angular,JiaLiPassion/angular,mhevery/angular,brandonroberts/angular,gdi2290/angular,mgechev/angular,sarunint/angular,wKoza/angular,shairez/angular,mprobst/angular,matsko/angular