failures re: independent column name encodings

[simonpcouch]

In recent runs on DBs + Posit Pro Drivers (Linux) / database, seeing:

── Failed tests ────────────────────────────────────────────────────────────────
Failure ('test-driver-sql-server.R:355:3'): independent encoding of column entries and names (#834)
`df` (`actual`) not identical to `res` (`expected`).

`names(actual)`:   "var_char_col" "bøvs"
`names(expected)`: "var_char_col" "b.vs"

`actual$var_char_col`:   "kanin" "ræven" "ålens" "ørred"
`expected$var_char_col`: "kanin" "r?ven" "?lens" "?rred"

`actual$bøvs` is a double vector (1, 1, 1, 1)
`expected$bøvs` is absent

`actual$b.vs` is absent
`expected$b.vs` is a double vector (1, 1, 1, 1)

[ FAIL 1 | WARN 0 | SKIP 408 | PASS 10246 ]

Related to #834—seems to be with Pro Drivers only?

Note that actual/expected are flipped in this test.