Bug: TestRelationSetAllTypes is flakey

[dylanlott]

Bug description

Occasionally running the tests for the Postgres connector results in an interface conversion panic. This is likely due to pglogrepl messages being received either out of order or at unexpected times.

=== RUN   TestRelationSetAllTypes
--- FAIL: TestRelationSetAllTypes (0.14s)
panic: interface conversion: pglogrepl.Message is *pglogrepl.CommitMessage, not *pglogrepl.RelationMessage [recovered]
        panic: interface conversion: pglogrepl.Message is *pglogrepl.CommitMessage, not *pglogrepl.RelationMessage

goroutine 11 [running]:
testing.tRunner.func1.2({0x1a41de0, 0xc00033c570})
        /usr/local/go/src/testing/testing.go:1389 +0x366
testing.tRunner.func1()
        /usr/local/go/src/testing/testing.go:1392 +0x5d2
panic({0x1a41de0, 0xc00033c570})
        /usr/local/go/src/runtime/panic.go:844 +0x258
github.com/conduitio/conduit-connector-postgres/source/logrepl/internal.TestRelationSetAllTypes(0xc0000036c0)
        /Users/dylanlott/dev/meroxa/conduit-connector-postgres/source/logrepl/internal/relationset_test.go:58 +0x61b
testing.tRunner(0xc0000036c0, 0x1b48c08)
        /usr/local/go/src/testing/testing.go:1439 +0x214
created by testing.(*T).Run
        /usr/local/go/src/testing/testing.go:1486 +0x725
FAIL    github.com/conduitio/conduit-connector-postgres/source/logrepl/internal 1.480s

Steps to reproduce

1. Run make run
2. The TestRelationSetAllTypes test occasionally fails with a failed interface type conversion.

Version

v0.1.0