ci: Add custom function to get version for Packit builds

Default for packit is the latest tag, but we want to use the
"next" version we already have set.

.packit.yaml

@@ -5,6 +5,8 @@ actions:
  - 'make'
  - 'make dist'
  - 'bash -c "ls *.tar*"'
+ get-current-version:
+ - 'bash -c "./configure --version | head -n1 | cut -f3 -d\" \""'
 
 jobs:
 - job: copr_build