fix: do not insist on predefined stages, let projects be free to choose their own
There is no need to explicitly define a
build stage by a generic pre-amble/template, the default implied stages of 'build', 'test', and 'deploy' should do just fine.
By not imposing a predefined list of stages we gain the following:
- It is easier for downstream projects to consume the
ci-before.yamltemplate and combine it with other templates/jobs that require other stages besides
buildfor some reason
- It is easier to add additional templates which smoothly integrate with the "defaults" out of the box for KDE CI pipelines.
A a good example of this is the work on static analysers that would automatically plug in at the