Significant cleanup x 15.

This commit is the next in a commit chain quietly resurrecting BETSE
for a modern audience and the modern Python ecosystem. Specifically,
this commit continues resolving failing GitHub Actions-based continuous
integration (CI) workflows. BETSE 1.4.0 is now still days from official
release, supposedly. (*Despised reprisals!*)

betse/util/io/error/errwarning.py

@@ -10,12 +10,9 @@
 
 # ....................{ IMPORTS                            }....................
 import sys, warnings
-from beartype.typing import (
-    ContextManager,
-    Generator,
-)
 from betse.util.io.log import logs
 from betse.util.type.types import ClassType
+from betse.util.type.typehints import ContextManagerOrGenerator
 from contextlib import contextmanager
 
 # ....................{ INITIALIZERS                       }....................
@@ -82,7 +79,7 @@ def init() -> None:
             logs.log_debug('Deferring to default warning policy.')
 
 # ....................{ MANAGERS                           }....................
-def ignoring_deprecations() -> ContextManager:
+def ignoring_deprecations() -> ContextManagerOrGenerator:
     '''
     Single-shot context manager temporarily ignoring all **deprecation
     warnings** (i.e., instances of the :class:`DeprecationWarning`,
@@ -104,7 +101,7 @@ def ignoring_deprecations() -> ContextManager:
 
 
 @contextmanager
-def ignoring_warnings(*warning_clses: ClassType) -> Generator:
+def ignoring_warnings(*warning_clses: ClassType) -> ContextManagerOrGenerator:
     '''
     Single-shot context manager temporarily ignoring *all* warnings of *all*
     passed warning types emitted by the :mod:`warnings` module for the duration

betse/util/type/typehints.py

@@ -11,13 +11,21 @@
 # ....................{ IMPORTS                            }....................
 from beartype.typing import (
     Annotated,
+    ContextManager,
+    Generator,
 )
 from beartype.vale import (
     IsAttr,
     IsEqual,
 )
 from numpy import ndarray
 
+# ....................{ HINTS                              }....................
+ContextManagerOrGenerator = ContextManager | Generator
+'''
+PEP-compliant type hint matching either a context manager *or* generator.
+'''
+
 # ....................{ HINTS ~ lib : numpy : 1d           }....................
 NDArrayNdim1 = Annotated[ndarray, IsAttr['ndim', IsEqual[1]]]
 '''