Get string till the last occurency, without that last character in regex

Question

I have a docker image name I have to trim.

Example name:

localhost:8080/mydockerimage-0.0.1:latest

I want to get the first part, till the tag, but without :.

I have written something like this:

.*\:

which partially matches my needs, however the result still ends with : - localhost:8080/mydockerimage-0.0.1:.

How can I unselect the last concurrency of :?