CI: PyPy3 testing (#44809)

Author: lithomas1

.github/workflows/posix.yml

@@ -31,6 +31,7 @@ jobs:
           [actions-38-slow.yaml, "slow", "", "", "", "", ""],
           [actions-38-locale.yaml, "not slow and not network", "language-pack-zh-hans xsel", "zh_CN.utf8", "zh_CN.utf8", "", ""],
           [actions-39-slow.yaml, "slow", "", "", "", "", ""],
+          [actions-pypy-38.yaml, "not slow and not clipboard", "", "", "", "", ""],
           [actions-39-numpydev.yaml, "not slow and not network", "xsel", "", "", "deprecate", "-W error"],
           [actions-39.yaml, "not slow and not clipboard", "", "", "", "", ""]
         ]

ci/deps/actions-pypy-38.yaml

@@ -0,0 +1,20 @@
+name: pandas-dev
+channels:
+  - conda-forge
+dependencies:
+  # TODO: Add the rest of the dependencies in here
+  # once the other plentiful failures/segfaults
+  # with base pandas has been dealt with
+  - python=3.8
+
+  # tools
+  - cython>=0.29.24
+  - pytest>=6.0
+  - pytest-cov
+  - pytest-xdist>=1.31
+  - hypothesis>=5.5.3
+
+  # required
+  - numpy
+  - python-dateutil
+  - pytz