How to get rid of old repositories after ODA Upgrade

Hi,

We upgraded our ODA from 19.6 to 19.9.

Now I want to make a Repository Cleanup.

# ll /opt/oracle/oak/pkgrepos/db/*
db/11.2.0.4.201020:
total 1289764
-r-xr-xr-x 1 root root       605 Oct 29 2020 componentmetadata.xml
-r-xr-xr-x 1 root root     31544 Oct 29 2020 p31143631_112040_Linux-x86-64.zip
-r-xr-xr-x 1 root root 1319384502 Oct 29 2020 p31718723_112040_Linux-x86-64.zip

db/18.12.0.0.201020:
total 2938028
-r-xr-xr-x 1 root root       959 Oct 29 2020 componentmetadata.xml
-r-xr-xr-x 1 root root     34492 Oct 29 2020 p31178058_1812000DBRU_Generic.zip
-r-xr-xr-x 1 root root 2998373467 Oct 29 2020 p31748523_180000_Linux-x86-64.zip
-r-xr-xr-x 1 root root   7179569 Oct 29 2020 p31843587_1812000DBRU_Linux-x86-64.zip

db/18.9.0.0.200114:
total 2543676
-r-xr-xr-x 1 root root       777 Apr 21 2020 componentmetadata.xml
-r-xr-xr-x 1 root root 2602169581 Apr 21 2020 p31027197_180000_Linux-x86-64.zip

db/19.6.0.0.200114:
total 2112404
-r-xr-xr-x 1 root root       549 Apr 21 2020 componentmetadata.xml
-r-xr-xr-x 1 root root 2160976478 Apr 21 2020 p30501910_190000_Linux-x86-64.zip

db/19.9.0.0.201020:
total 2799532
-r-xr-xr-x 1 root root      1025 Oct 29 2020 componentmetadata.xml
-r-xr-xr-x 1 root root 2856496584 Oct 29 2020 p31750108_190000_Linux-x86-64.zip
-r--r--r-- 1 root root   7406838 Oct 29 2020 p31902534_199000DBRU_Linux-x86-64.zip