update SQLite snap

[simonpcouch]

Closes #1562. We'll still see some unrelated postgres GHA failures on this PR.

We first saw this failure on 11/20, 3 days after RSQLite 2.3.8 was released on 11/17. If I downgrade with pak::pak("r-dbi/RSQLite@v2.3.7"), I see the snap change this PR proposes reverted:

> pak::pak("r-dbi/RSQLite@v2.3.7")
                                                                        
→ Will update 1 package.
→ The package (0 B) is cached.
+ RSQLite 2.3.8 → 2.3.7 👷🏼🔧 (GitHub: 7588a97)

! RSQLite is loaded in the current R session, you probably need to
restart R after the installation.

? Do you want to continue (Y/n) Y
ℹ No downloads are needed, 1 pkg is cached
✔ Got RSQLite 2.3.7 (source) (5.24 MB)
ℹ Packaging RSQLite 2.3.7
✔ Packaged RSQLite 2.3.7 (5.1s)                                    
ℹ Building RSQLite 2.3.7                                           
✔ Built RSQLite 2.3.7 (36.6s)                                      
✔ Installed RSQLite 2.3.7 (github::r-dbi/RSQLite@7588a97) (33ms)     
✔ 1 pkg + 15 deps: kept 15, upd 1, dld 1 (NA B) [49.7s]              

Restarting R session...

> devtools:::test_active_file()
Registering testing src: sqlite OK
Registering testing src: MariaDB 
* Failed to connect: Can't connect to local server through socket '/tmp/mysql.sock' (2)
Registering testing src: postgres OK
[ FAIL 1 | WARN 0 | SKIP 0 | PASS 21 ]

── Failure (test-backend-sqlite.R:108:3): can explain a query ──────────────────
Snapshot of code has changed:
old[8:11] vs new[8:11]
    
    <PLAN>
      id parent notused                                        detail
-   1  2      0      35 SEARCH test USING COVERING INDEX test_x (x>?)
+   1  2      0       0 SEARCH test USING COVERING INDEX test_x (x>?)

* Run testthat::snapshot_accept('backend-sqlite') to accept the change.
* Run testthat::snapshot_review('backend-sqlite') to interactively review the change.
[ FAIL 1 | WARN 0 | SKIP 0 | PASS 21 ]