Bump rexml from 3.2.5 to 3.2.8 (#12978)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -143,12 +143,14 @@ GEM
     open4 (1.3.4)
     public_suffix (4.0.6)
     rchardet (1.8.0)
-    rexml (3.2.5)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     ruby-macho (2.5.1)
     ruby2_keywords (0.0.5)
     sawyer (0.8.2)
       addressable (>= 2.3.5)
       faraday (> 0.8, < 2.0)
+    strscan (3.1.0)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
     typhoeus (1.4.1)