Bump sphinxcontrib-serializinghtml from 1.1.4 to 1.1.5 in /requirements (#17206)
Bump sphinxcontrib-serializinghtml from 1.1.4 to 1.1.5 in /requirements (#17206)

Bumps [sphinxcontrib-serializinghtml](http://sphinx-doc.org/) from 1.1.4 to 1.1.5.

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
bqbn/addons-server,mozilla/addons-server,diox/olympia,diox/olympia,diox/olympia,mozilla/addons-server,mozilla/olympia,mozilla/olympia,wagnerand/addons-server,mozilla/olympia,wagnerand/addons-server,wagnerand/addons-server,mozilla/addons-server,bqbn/addons-server,bqbn/addons-server,mozilla/olympia,bqbn/addons-server,mozilla/addons-server,diox/olympia,wagnerand/addons-server