Bump rexml from 3.2.6 to 3.2.8 in /docs (#863)

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

docs/Gemfile.lock

@@ -111,7 +111,8 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.2.6)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     rouge (4.2.1)
     ruby-rc4 (0.1.5)
     safe_yaml (1.0.5)
@@ -121,6 +122,7 @@ GEM
       google-protobuf (>= 3.25, < 5.0)
     sass-embedded (1.77.0-x86_64-linux-gnu)
       google-protobuf (>= 3.25, < 5.0)
+    strscan (3.1.0)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
     timers (4.3.5)