python3-sphinx-rtd-theme: upgrade 1.0.0 -> 1.1.0

Changelog:
https://sphinx-rtd-theme.readthedocs.io/en/stable/changelog.html



Signed-off-by: Zheng Ruoqin <zhengrq.fnst@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>