Increase git fetch depth on CI builds to allow rebuild older commits
(This one is for Fredrik. )
The Azure CI builds use a fetch depth of 1 in order to try to reduce the download size needed for the builds.
However, this means that if somebody else merges to master after your PR merges (and you want to rebuild your commit) then the CI builds fail as they don't fetch the commit.
We should consider increasing the fetch depth to something larger than 1, perhaps 10, in order to allow the rebuilding of previous commits.
Note: Should do this after the VS2019 changes, since they are adding more build bots.