Do not update `no_clean` option value on PreviousBuildDirError

Since a recent refactoring of our temporary directory handling,
`no_clean` is only read prior to these `except` blocks. Since it's not
needed, remove it!

src/pip/_internal/commands/install.py

@@ -23,11 +23,7 @@ from pip._internal.cli import cmdoptions
 from pip._internal.cli.cmdoptions import make_target_python
 from pip._internal.cli.req_command import RequirementCommand, with_cleanup
 from pip._internal.cli.status_codes import ERROR, SUCCESS
-from pip._internal.exceptions import (
-    CommandError,
-    InstallationError,
-    PreviousBuildDirError,
-)
+from pip._internal.exceptions import CommandError, InstallationError
 from pip._internal.locations import distutils_scheme
 from pip._internal.operations.check import check_install_conflicts
 from pip._internal.req import install_given_reqs
@@ -438,9 +434,6 @@ class InstallCommand(RequirementCommand):
                 logger.error(message, exc_info=show_traceback)
 
                 return ERROR
-            except PreviousBuildDirError:
-                options.no_clean = True
-                raise
 
         if options.target_dir:
             self._handle_target_dir(

src/pip/_internal/commands/wheel.py

@@ -12,7 +12,7 @@ import shutil
 from pip._internal.cache import WheelCache
 from pip._internal.cli import cmdoptions
 from pip._internal.cli.req_command import RequirementCommand, with_cleanup
-from pip._internal.exceptions import CommandError, PreviousBuildDirError
+from pip._internal.exceptions import CommandError
 from pip._internal.req.req_tracker import get_requirement_tracker
 from pip._internal.utils.misc import ensure_dir, normalize_path
 from pip._internal.utils.temp_dir import TempDirectory
@@ -127,7 +127,7 @@ class WheelCommand(RequirementCommand):
         with get_requirement_tracker() as req_tracker, TempDirectory(
             options.build_dir, delete=build_delete, kind="wheel"
         ) as directory:
-            try:
+            if True:  # Keep block indented temporarily, for a cleaner commit
                 reqs = self.get_requirements(
                     args, options, finder, session,
                     wheel_cache
@@ -186,6 +186,3 @@ class WheelCommand(RequirementCommand):
                     raise CommandError(
                         "Failed to build one or more wheels"
                     )
-            except PreviousBuildDirError:
-                options.no_clean = True
-                raise