Fix test collection for Connection and Variables for non-db tests

[potiuk]

When Tests were collected for microsoft provider alone for non-db tests, Connection were used in "parametrized" to perameterize the tests. This was only working accidentally so far because all ORM models were loaded before in other tests - including Triggers -and then the connection objects did not trigger any DB operations. But when microsoft provider tests were run first (and in separation), the Triggers were not imported and Connection creation caused error:

When initializing mapper mapped class AssetModel->asset, expression
'Trigger' failed to locate a name ('Trigger') # Please enter the commit
message for your changes. Lines starting

This can be mitigated (as already advised in unit tests documentation) by replacing Connections with MagicMock.

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[potiuk]

Discovered when looking why #45249 has been failing - very interesting side-effect in our tests

[gopidesupavan]

Interesting one :)

[potiuk]

Interesting one :)

Indeed - we should likely improve some of the diagnostics there and fail "earlier" and with "clearer" message - but for now this one should be "good enough"