DEV: Update default Python in benchmark config.

Author: rossbar

benchmarks/asv.conf.json

@@ -35,7 +35,7 @@
 
     // The Pythons you'd like to test against.  If not provided, defaults
     // to the current version of Python used to run `asv`.
-    "pythons": ["3.7"],
+    // "pythons": ["3.9"],
 
     // The matrix of dependencies to test.  Each key is the name of a
     // package (in PyPI) and the values are version numbers.  An empty

benchmarks/asv_compare.conf.json.tpl

@@ -39,7 +39,7 @@
 
     // The Pythons you'd like to test against.  If not provided, defaults
     // to the current version of Python used to run `asv`.
-    "pythons": ["3.7"],
+    // "pythons": ["3.9"],
 
     // The matrix of dependencies to test.  Each key is the name of a
     // package (in PyPI) and the values are version numbers.  An empty