fix: fix various schema engine test issues

[jacek-prisma]

TML-1501

Removes postgres 9, 10 and 11 from the CI. Also includes some minor test fixes for issues that were unnoticed becuase of the workflow being broken.

/test-all

[codspeed-hq]

CodSpeed Performance Report

Merging #5647 will not alter performance

_{Comparing fix/fix-se-ci (59b9518) with main (9bf76db)}

Summary

✅ 11 untouched

[github-actions]

WASM Query Engine File Size

Engine	This PR	Base branch	Diff
Postgres	2.191MiB	2.191MiB	0.000B
Postgres (gzip)	867.881KiB	867.880KiB	1.000B
Mysql	2.159MiB	2.159MiB	0.000B
Mysql (gzip)	854.665KiB	854.662KiB	3.000B
Sqlite	2.071MiB	2.071MiB	0.000B
Sqlite (gzip)	820.103KiB	820.101KiB	2.000B
SQL Server	2.130MiB	2.130MiB	0.000B
SQL Server (gzip)	845.642KiB	845.641KiB	1.000B
CockroachDB	2.213MiB	2.213MiB	0.000B
CockroachDB (gzip)	876.966KiB	876.965KiB	1.000B

WASM Query Compiler File Size

Engine	This PR	Base branch	Diff
Postgres	1.859MiB	1.859MiB	0.000B
Postgres (gzip)	733.869KiB	733.869KiB	0.000B
Mysql	1.825MiB	1.825MiB	0.000B
Mysql (gzip)	722.148KiB	722.148KiB	0.000B
Sqlite	1.783MiB	1.783MiB	0.000B
Sqlite (gzip)	704.437KiB	704.437KiB	0.000B
SQL Server	1.856MiB	1.856MiB	0.000B
SQL Server (gzip)	735.097KiB	735.097KiB	0.000B
CockroachDB	1.884MiB	1.884MiB	0.000B
CockroachDB (gzip)	743.478KiB	743.478KiB	0.000B