A /var partition of 5G is woefully small for all but the very tiniest of systems.
We would need to see the lsblk -f output for the entire system as well as the output of df -h so we can see what is used and available everywhere before we can make reasonable suggestions so solve the problem.
It is always a good idea to provide more info that you think is needed since it may be something you overlooked that provides the clues on how to fix the problems.
Just for reference, you might note that /var/lib/sn... which I interpret as /var/lib/snap` indicates the partition is 94% used.
More info will assist in answering the question about lack of space – resizing storage.
I can’t see the same message you get when I open the link on a Firefox 120.0.1 (64-bit).
Could you rephrase your message and explain what’s the concern with the mirror? I been using it for years, because due my geographic location it defaults to said mirror.
If you click on the link you posted, will you get the file downloaded to your HD? I just get a message with a red exclamation mark, while clicking on the mark I get the message I attached.
Firefox is blocking content from http sites (you have to confirm to access this type of content). Even if the content gets delivered with a https in the end (they just made a forwarding from HTTP to HTTPS) So to avoid troubles with the mirrors, admins from this type of domains, would be advised to configure HTTP as HTTPS direct, then apps like Firefox would not complain.
-y, --assumeyes automatically answer yes for all questions
And an other point is, if you use dnf with -y you will loose a lot of verbose output to debug your issue. The -y option is for experts who know what they do (to automate the process with a script).
Please try the commands again without -y to see which output you get.
enlarge /var to an adequate size. (I recommend at least 50 GB)
or
merge /var into the root file system then the space currently used by /var wold be available for other use.
I would recommend option 2 since the root file system is currently only 13% occupied with 13G data and /var is using 4.4G data. Merging the /var data into / should result in still using <20% of the root file system with about 18G data
/var contains all of the log files, cache files, and other files that routinely grow or shrink over time so it must have adequate space to prevent problems such as you already encountered.