fix(releaser): don't put license in root directory on apt installation

relates to STACKITCLI-324 and #1265

Author: rubenhoenle

.goreleaser.yaml

@@ -105,7 +105,9 @@ nfpms:
     license: Apache 2.0
     contents:
       - src: LICENSE.md
-        dst: LICENSE.md
+        dst: /usr/share/doc/stackit/copyright
+        file_info:
+          mode: 0644
     formats:
       - deb
       - rpm