I don't know if it may be the right approach for you, but what I did is downgrade my version of MySQL Workbench to 6.3 and uninstalled the previous version and it will then give you the "if available" option for SSL. As you are right, it is not the case for previous versions, however you do lose a few more modern features in the process.

https://downloads.mysql.com/archives/workbench/

Another solution as well is to connect to connect to the database in 6.3 and since the configuration saves are in same location, upgrade to 8.0 where it will still have the old configuration file and won't use SSL due to backwards compatibility.

I solved this by editing the connections.xml configuration file.

Under ~/.mysql/workbench/connections.xml I searched for the connection name and changed

<value type="int" key="useSSL">2</value>

to

<value type="int" key="useSSL">1</value>

MySQL Workbench has release 8.0.28,slove this bug, wow, happy.

====
In macos also has this issue. My version is mysql-workbench-community-8.0.27-macos-x86_64.dmg

I have downgrade to mysql-workbench-community-8.0.26-macos-x86_64.dmg and solve it.

===
this issue has been report to mysql team,see

https://bugs.mysql.com/bug.php?id=105327
===2021-12-05 Edit
In the bug report,the develop team reply this issue will be fixed in 8.0.28. ===2021-12-08 Edit
Someone maybe waiting for the fix , so I put the download page link here, so we can check the newest version quickly. https://dev.mysql.com/downloads/workbench/

I found this solution on Stack Exchange and worked for me just fine on Windows 10. This is the original post: https://dba.stackexchange.com/questions/199154/mysql-workbench-ssl-is-required-but-the-server-doesnt-support-it.

Look for the 'fehrlich' answer and please, give the credits. I will describe it here as in the original post.:

You can bring back the old SSL options in 8.0.27:

• Close MySQL Workbench
• Go to you MySQL Workbench install folder (p.e. C:\Program Files\MySQL\MySQL Workbench 8.0 CE)
• open the file modules/data/mysql_rdbms_info.xml
• replace all occurrences of
• ">2|Require,3|Require and Verify CA,4|Require and Verify Identity"
• with ">0|No,1|If available,2|Require,3|Require and Verify CA,4|Require and Verify Identity"

Now you have the old options back.

Original image

Here is the correct solution for version +8.0.x. When the program starts, the edited configuration files are changed again.

Therefore, you need to add useSSL=1 in advanced.

I am using mysql server 5.6, uninstall and install workbench 8. it's work