Bump webob from 1.8.6 to 1.8.7 in /requirements (#16586)

Bumps [webob](https://github.com/Pylons/webob) from 1.8.6 to 1.8.7.
- [Release notes](https://github.com/Pylons/webob/releases)
- [Changelog](https://github.com/Pylons/webob/blob/1.8.7/CHANGES.txt)
- [Commits](https://github.com/Pylons/webob/compare/1.8.6...1.8.7)

Signed-off-by: dependabot[bot] <support@github.com>

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

requirements/tests.txt

@@ -111,9 +111,9 @@ PyBrowserID==0.14.0 \
 hawkauthlib==2.0.0 \
     --hash=sha256:935878d3a75832aa76f78ddee13491f1466cbd69a8e7e4248902763cf9953ba9 \
     --hash=sha256:effd64a2572e3c0d9090b55ad2180b36ad50e7760bea225cb6ce2248f421510d
-WebOb==1.8.6 \
-    --hash=sha256:a3c89a8e9ba0aeb17382836cdb73c516d0ecf6630ec40ec28288f3ed459ce87b \
-    --hash=sha256:aa3a917ed752ba3e0b242234b2a373f9c4e2a75d35291dcbe977649bd21fd108
+WebOb==1.8.7 \
+    --hash=sha256:73aae30359291c14fa3b956f8b5ca31960e420c28c1bec002547fb04928cf89b \
+    --hash=sha256:b64ef5141be559cfade448f044fa45c2260351edcb6a8ef6b7e00c7dcef0c323
 wcwidth==0.2.5 \
     --hash=sha256:beb4802a9cebb9144e99086eff703a642a13d6a0052920003a230f3294bbe784 \
     --hash=sha256:c4d647b99872929fdb7bdcaa4fbe7f01413ed3d98077df798530e5b04f116c83