feat: replace deprecated call to getVarcharTypeDeclarationSQL()

[Chris53897]

Needs ci run for --prefer-lowest

[johanwilfer]

Do you know if this is a BC break?

[Chris53897]

I guess not.
That depends on the minimum version of dbal.
--prefer-lowest is Locking doctrine/dbal (3.8.0) Need to check if that is generally ok.
Deprecated in https://github.com/doctrine/dbal/releases/tag/3.4.0
But i don't know in which version the function was added.
https://github.com/doctrine/dbal/releases?q=getStringTypeDeclarationSQL&expanded=true

Internally the function is still used in dbal.
If there is a new major version 7 anyway, i suggest to just merge it for the new version. To be 100% safe.

[johanwilfer]

Will merge this, seems we had a mistake with orm 3 support anyway. Better to remove deprecations in the minor version then.