Update commons-io:commons-io to 2.20.0

Release notes:
- https://commons.apache.org/proper/commons-io/changes.html#a2.19.0
- https://commons.apache.org/proper/commons-io/changes.html#a2.20.0

Release-Notes: Update commons-io:commons-io to 2.20.0
Change-Id: I4b3c2007ab15d416b5317949eafcd2d965645716

tools/nongoogle.bzl

diff --git a/tools/nongoogle.bzl b/tools/nongoogle.bzl
index 11125d7..4fdc091 100644
--- a/tools/nongoogle.bzl
+++ b/tools/nongoogle.bzl
@@ -186,8 +186,8 @@
 
     maven_jar(
         name = "commons-io",
-        artifact = "commons-io:commons-io:2.18.0",
-        sha1 = "44084ef756763795b31c578403dd028ff4a22950",
+        artifact = "commons-io:commons-io:2.20.0",
+        sha1 = "36f3474daec2849c149e877614e7f979b2082cd2",
     )
 
     # Google internal dependencies: these are developed at Google, so there is