[Maintenance] Replace dbal conflict with explicit requirement

[lchrusciel]

Q	A
Branch?	1.9
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Related tickets	mentioned in #13215 (review)
License	MIT

[Zales0123]

Thank you, Łukasz! 🥇

[stloyd]

IMHO that conflict & explain was way more useful than just locking to explicit version, cause with explain, anyone who will struggle to update to v3 will be able to see related problem & issue instead of looking for everything on his/her own...

[lchrusciel]

Hey @stloyd, I can totally understand you. On the contrary, we know, that 2.* is the version supported, but 3.* is not due to the semver. We are basing our build on this explicit version atm.
Perhaps, something similar to the CONFLICT.md file for dependencies log would be useful as well. Or maybe these kinds of changes should be documented in ADRs? What do you think?

[stloyd]

I would say:

• this was clearly a hidden bug about missing dependency declaration, which lead to i.e. Unknown column type "json_array" #13211,
• ADR is IMHO good but when you add new required dependency, but as above this one was already here "since beginning" but not clearly pointed out,
• CONFLICT.md note is the way to go IMHO when you need to lock dependency due too bug, either by conflict or by explicit version lock (which is what happen here & was handled in Add conflict with doctrine/dbal ^3 to avoid missing json_array doctrine type error #13215),

So I would suggest:

• revert CONFLICT.md changes to state in Add conflict with doctrine/dbal ^3 to avoid missing json_array doctrine type error #13215,
• leave explicit version lock in composer.json done here,