N: Skipping acquire of configured file 'universe/binary-i386/Packages' as ... doesn't support architecture 'i386'

I'm trying to upgrade my Ubuntu from version 18.04 to version 20.04. When I run sudo apt udate I receive the following error:

N: Skipping acquire of configured file 'universe/binary-i386/Packages' as repository 'https://repos.codelite.org/ubuntu bionic InRelease' doesn't support architecture 'i386'

I also cannot update to Ubuntu 20 when I run sudo update-manager -d and I receive the following error:

Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.

update: The first error was resolved! But I still cannot update to Ubuntu 20. when I run sudo apt update, I get:

Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:2 http://dl.google.com/linux/chrome/deb stable InRelease                   
Hit:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease                
Hit:4 http://archive.ubuntu.com/ubuntu bionic-backports InRelease              
Hit:5 https://repos.codelite.org/ubuntu bionic InRelease                       
Hit:6 http://archive.ubuntu.com/ubuntu bionic-security InRelease               
Hit:7 https://packages.microsoft.com/ubuntu/18.04/prod bionic InRelease        
Hit:8 https://cloud.r-project.org/bin/linux/ubuntu bionic-cran35/ InRelease    
Get:9 https://desktop-download.mendeley.com/download/apt stable InRelease [2,456 B]
Hit:10 http://ppa.launchpad.net/plushuang-tw/uget-stable/ubuntu bionic InRelease
Hit:11 http://ppa.launchpad.net/smathot/cogscinl/ubuntu bionic InRelease       
Hit:12 http://ppa.launchpad.net/uget-team/ppa/ubuntu bionic InRelease          
Fetched 2,456 B in 2s (1,396 B/s)
Reading package lists... Done
Building dependency tree       
Reading state information... Done
1 package can be upgraded. Run 'apt list --upgradable' to see it.

When I run sudo apt upgrade, I get:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Following the note from update, I run apt list --upgradable and the output is

python-datamatrix/bionic,bionic 0.10.17-1 all [upgradable from: 0.10.3-1]

The default Python version on mu Ubuntu is Python 3.6.9

For the first problem, refer to the answer Skippping acquire configured file - doesn't support architecture 'i386' You must find the file located in /etc/apt where the string 'repos.codelite.org' is present and add the string '[arch=amd64]'. In this way only the packages for the correct architecture are installed.

For the second problem (the one related to the OS updated), according to the output you showed in your question, I suggested you to update the package python-datamatrix running: pip3 install python-datamatrix

However, according to your feedback (you were not able to solve), it's best to remove it (as suggested in karel's answer): pip3 uninstall python-datamatrix

For this answer, I referred also to Error while trying to upgrade from Ubuntu 18.04 to 18.10: "Please install all available updates for your release before upgrading." and Can't upgrade Ubuntu 18.04 to 20.04 because of "Please install all available updates for your release before upgrading" error