Use rename-mime-file

container.yaml

@@ -23,6 +23,7 @@ flatpak:
         - qalculate
     command: labplot
     rename-icon: labplot
+    rename-mime-file: labplot.xml
     finish-args: |-
         --device=dri
         --filesystem=host
@@ -37,4 +38,3 @@ flatpak:
     cleanup-commands: |
         rm -fr /app/include/
         rm -f /app/lib64/qt6/plugins/cantor/backends/cantor_{octave,sage,scilab}backend.so
-        mv /app/share/mime/packages/{,org.kde.}labplot.xml