Revert "TMP: pin openssl for doc build (pandas-dev#28404)" (pandas-dev#28405)

This reverts commit 094fb12.

Author: jorisvandenbossche

environment.yml

@@ -82,7 +82,3 @@ dependencies:
   - xlwt  # pandas.read_excel, DataFrame.to_excel, pandas.ExcelWriter, pandas.ExcelFile
   - odfpy  # pandas.read_excel
   - pyreadstat  # pandas.read_spss
-
-  # temporarily pin openssl
-  # https://github.com/pandas-dev/pandas/issues/28402
-  - openssl=1.1.1c

scripts/generate_pip_deps_from_conda.py

@@ -19,7 +19,7 @@
 
 import yaml
 
-EXCLUDE = {"python=3", "openssl=1.1.1c"}
+EXCLUDE = {"python=3"}
 RENAME = {"pytables": "tables", "pyqt": "pyqt5"}