perf: Use Rich Status for batched spinner rendering instead of per-line updates

news/14028.feature.rst

@@ -0,0 +1 @@
+Consolidate spinner and progress bar functionality into a unified ``ui`` module and switch to Rich's ``Status`` context manager for proper spinner rendering. This improves performance by eliminating per-line syscall overhead and enabling Rich's optimized terminal batching, while fixing issues with ANSI codes appearing in test output.

src/pip/_internal/build_env.py

@@ -19,7 +19,7 @@
 from pip._vendor.packaging.version import Version
 
 from pip import __file__ as pip_location
-from pip._internal.cli.spinners import open_rich_spinner, open_spinner
+from pip._internal.cli.ui import status
 from pip._internal.exceptions import (
     BuildDependencyInstallError,
     DiagnosticPipError,
@@ -254,11 +254,10 @@ def install(
         identify_requirement = (
             f" for {for_req.name}" if for_req and for_req.name else ""
         )
-        with open_spinner(f"Installing {kind}") as spinner:
+        with status(f"Installing {kind}"):
             call_subprocess(
                 args,
                 command_desc=f"installing {kind}{identify_requirement}",
-                spinner=spinner,
                 **extra_environ,
             )
 
@@ -331,7 +330,7 @@ def install(
             # Hide the logs from the installation of build dependencies.
             # They will be shown only if an error occurs.
             capture_ctx: ContextManager[StringIO] = capture_logging()
-            spinner: ContextManager[None] = open_rich_spinner(f"Installing {kind}")
+            spinner: ContextManager[None] = status(f"Installing {kind}")
         else:
             # Otherwise, pass-through all logs (with a header).
             capture_ctx, spinner = nullcontext(StringIO()), nullcontext()