nix(loadtest): remove jwt-cache-worst

This test is not really functional (anymore?). It depends on some tokens
expiring - but they don't, really. This is because:
1) Before merging the RSA and HS variants earlier in this patch series,
they ran roughly 15s and 34s respectively in CI.
2) Since PostgREST takes a clock skew of up to 30 seconds into account,
there would be *at most* 4s of expiring tokens in a test run - and
*only* in the HS case, not for RSA.

nix/tools/loadtest.nix

@@ -76,18 +76,6 @@ let
             ${runner} -lazy -targets gen_targets.http -output \"$abs_output\" \"''${_arg_leftovers[@]}\""
             ;;
 
-          jwt-cache-worst)
-            export PGRST_JWT_SECRET="@$_arg_testdir/gen_jwks.json"
-
-            ${libfaketime}/bin/faketime '2000-01-01 00:00:00' ${genTargets} --worst "$_arg_testdir"
-
-            # shellcheck disable=SC2145
-            ${withTools.withPg} -f "$_arg_testdir"/fixtures.sql \
-            ${withTools.withPgrst} --faketime '2000-01-01 00:00:00' -m "$_arg_monitor" \
-            sh -c "cd \"$_arg_testdir\" && \
-            ${runner} -lazy -targets gen_targets.http -output \"$abs_output\" \"''${_arg_leftovers[@]}\""
-            ;;
-
           # here we sleep purposefully to check how much memory does the schema cache consume in the final report
           mixed)
             # shellcheck disable=SC2145