fix(build-newer-r): pass the system CA bundle to the ABI-verdict query (#241)

Follow-up to #240.
The bulk skip in `build-newer-r.R` never took effect: in all 16 `process-updates` runs on `773add0` (14300–14315) the ABI-verdict query failed with `root certificate file "/root/.postgresql/root.crt" does not exist`.
The fallback did its job: every run logged `0 of 1323 already carry a binary … 1323 left for bincraft` and built exactly as before. So nothing broke, but the run saved no time either.

## Changes

- `local/build-newer-r.R`: pass `sslrootcert = bincraft::postgres_sslrootcert("verify-full")` to the connection, as every other DB script in `local/` already does. With `verify-full` and no `sslrootcert`, libpq looks for `~/.postgresql/root.crt`.

## Verification

- In the `build-env-ubuntu:jammy`, `build-env-redhat:9` and `build-env-alpine:3.24` images, connecting with the distro's CA bundle gets past TLS verification to password authentication (tested with a deliberately wrong password).
- The S3 listings in the same runs logged no errors.

## Behaviour change

- The next runs should log a non-zero "N of M already carry a binary at their routed path" count and skip those candidates without calling bincraft.

Reviewed-on: #241

local/build-newer-r.R

@@ -71,7 +71,8 @@ if ("--dry-run" %in% args) {
           port = 15432,
           user = "rpkgs",
           password = Sys.getenv("PGPASS"),
-          sslmode = "verify-full"
+          sslmode = "verify-full",
+          sslrootcert = bincraft::postgres_sslrootcert("verify-full")
         )
         on.exit(DBI::dbDisconnect(con), add = TRUE)
         rows <- DBI::dbGetQuery(