Git commits in Moodle 3.11.1 by Dongsheng Cai

commit ecae6484a4f6343b04b0920f3eaa8b3149f592fa
Author: Dongsheng Cai <d@tux.im>
Date:   Tue, 06 Jul 2021 14:55:21 +0800
Tag:    v3.11.1

MDL-71978 core_calendar: only allow owner to edit user subscriptions


commit e280853f7aea1ae5e7f3d0197fce379ef59a3fe2
Author: Dongsheng Cai <d@tux.im>
Date:   Fri, 28 May 2021 10:34:12 +0800
Tag:    v3.11.1

MDL-70846 accessibility: update color to increase contrast


commit a246699a2ba2a45ef7e2c1e16331224eaa688c72
Author: Dongsheng Cai <d@tux.im>
Date:   Tue, 25 May 2021 18:38:51 +0800
Tag:    v3.11.1

MDL-70846 accessibility: update tree attributes to pass a11y check


commit 5464f370177914dbd1d81f15b7fe4379d1eaf21a
Author: Dongsheng Cai <d@tux.im>
Date:   Tue, 18 May 2021 18:36:49 +0800
Tag:    v3.11.1

MDL-65203 template: tab should be quoted to produce valid json