DOC: fix SA01 for pandas.errors.SpecificationError (#59983)

Author: tuhinsharma121

ci/code_checks.sh

@@ -169,7 +169,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         -i "pandas.errors.PerformanceWarning SA01" \
         -i "pandas.errors.PossibleDataLossError SA01" \
         -i "pandas.errors.PossiblePrecisionLoss SA01" \
-        -i "pandas.errors.SpecificationError SA01" \
         -i "pandas.errors.UndefinedVariableError PR01,SA01" \
         -i "pandas.errors.UnsortedIndexError SA01" \
         -i "pandas.errors.UnsupportedFunctionCall SA01" \

pandas/errors/__init__.py

@@ -444,6 +444,11 @@ class SpecificationError(Exception):
     The second way is calling ``agg`` on a Dataframe with duplicated functions
     names without assigning column name.
 
+    See Also
+    --------
+    DataFrame.agg : Aggregate using one or more operations over the specified axis.
+    Series.agg : Aggregate using one or more operations over the specified axis.
+
     Examples
     --------
     >>> df = pd.DataFrame({"A": [1, 1, 1, 2, 2], "B": range(5), "C": range(5)})