`lineage-20` docker image needs to be pushed to dockerhub

Never mind

The lineage-20.0 branch is already pushed, and it's out of date and doesn't work any more because it's missing the latest commits

Log output

``` error: Cannot checkout LineageOS/android_external_chromium-webview_prebuilt_x86_64 error: Unable to fully sync the tree error: Checking out local projects failed. Failing repos: external/chromium-webview/prebuilt/arm64 external/chromium-webview/prebuilt/x86 external/chromium-webview/prebuilt/x86_64 ```

for builds to work they need to use the latest or master tags. The build server seems to do that, even though the tag isn't present in the docker run ... command. Local builds need to specify the tag, other wise they pick up out-of-date builds (see recent comments in #335) I have the following images on my machine. If I call docker run... with no tag for lineageos-20.0 branch it runs the latest <none> image 85e4b980063f, which fails

$ docker images
REPOSITORY                             TAG          IMAGE ID       CREATED        SIZE
lineageos4microg/docker-lineage-cicd   latest       fb3dd536126a   8 weeks ago    2.05GB
lineageos4microg/docker-lineage-cicd   master       fb3dd536126a   8 weeks ago    2.05GB
lineageos4microg/docker-lineage-cicd   lineage-20   60aa571d62d4   6 months ago   2.06GB
lineageos4microg/docker-lineage-cicd   <none>       85e4b980063f   9 months ago   2.05GB
lineageos4microg/docker-lineage-cicd   <none>       e7b5f8b26633   9 months ago   2.05GB

I'll close this issue and raise another to sort out which images to use, and update the README if needed

lineageos4microg / docker-lineage-cicd

`lineage-20` docker image needs to be pushed to dockerhub #439