test(procmgr): revert unrelated Windows E2E refactor from spawn-profiles PR

Restore procmgr_win_test.go to main and drop the extracted helpers file.
The only E2E delta on this PR is removing the PAR test for #54735.

Author: jose-manuel-almaza

test/new-e2e/tests/agent-runtimes/procmgr/BUILD.bazel

@@ -5,15 +5,13 @@ dd_agent_go_test(
     srcs = [
         "procmgr_common_test.go",
         "procmgr_nix_test.go",
-        "procmgr_win_helpers_test.go",
         "procmgr_win_test.go",
     ],
     deps = [
         "//pkg/fleet/installer/packages/embedded",
         "//test/e2e-framework/components/datadog/agentparams",
         "//test/e2e-framework/components/os",
         "//test/e2e-framework/scenarios/aws/ec2",
-        "//test/e2e-framework/testing/components",
         "//test/e2e-framework/testing/e2e",
         "//test/e2e-framework/testing/environments",
         "//test/e2e-framework/testing/provisioners/aws/host",