add: pytest-asyncio>=0.19.0

pytest-asyncio>=0.19.0

Closes pandas-dev#48361.

No version guidance available so went for latest.  No-one should be messing around with tests without modern installs.

setup.cfg

@@ -53,6 +53,7 @@ test =
     hypothesis>=5.5.3
     pytest>=6.0
     pytest-xdist>=1.31
+    pytest-asyncio>=0.19.0
 # optional extras for recommended dependencies
 # see: doc/source/getting_started/install.rst
 performance =
@@ -137,6 +138,7 @@ all =
     pyreadstat>=1.1.2
     pytest>=6.0
     pytest-xdist>=1.31
+    pytest-asyncio>=0.19.0
     python-snappy>=0.6.0
     pyxlsb>=1.0.8
     scipy>=1.7.1