ci: bump docker image

Author: benoit-pierre

.github/workflows/build.yml

@@ -11,7 +11,7 @@ defaults:
     shell: bash --noprofile --norc -eo pipefail {0}
 
 env:
-  BASH_ENV: '/root/.bashrc'
+  BASH_ENV: '/home/ko/.bashrc'
 
 jobs:
 
@@ -25,8 +25,7 @@ jobs:
     name: ${{ matrix.variant }}
     runs-on: ubuntu-latest
     container:
-      image: koreader/koandroid:0.8.3-20.04
-      options: --user root
+      image: koreader/koandroid:0.9.1-22.04
 
     steps:
 
@@ -40,9 +39,6 @@ jobs:
           fetch-tags: true
           show-progress: false
 
-      - name: Fix checkout ownership
-        run: chown 'root:root' .
-
       # }}}
 
       # Build. {{{