ci: support pre-releases

GoReleaser automatically deteccts these patterns as pre-releases:
- vx.y.z-rcN
- vx.y.z-alphaN
- vx.y.z-betaN
- vx.y.z-preN

Signed-off-by: Leo Di Donato <[email protected]>

Author: leodido

.goreleaser.yaml

@@ -31,3 +31,6 @@ changelog:
     exclude:
       - "^docs:"
       - "^test:"
+
+release:
+  prerelease: auto