[bootstrap] use --update-specs during conda install

For some reason when bootstrap installs bob.devtools in the CI of other packages, it does not update all packages. I think this might lead to broken base environments.

enabled an automatic merge when the pipeline for 5ad38c33 succeeds

merged

mentioned in commit c418db2a

This seems to solve the issues in bob.learn.em and bob.learn.tensorflow

thanks @amohammadi :-)