Add some more resiliency to DB errors

PluralKit.Bot/Utils/MiscUtils.cs

@@ -52,6 +52,9 @@ namespace PluralKit.Bot
             // Ignore "Database is shutting down" error
             if (e is PostgresException pe && pe.SqlState == "57P03") return false;
             
+            // Ignore thread pool exhaustion errors
+            if (e is NpgsqlException npe && npe.Message.Contains("The connection pool has been exhausted")) return false;
+
             // This may expanded at some point.
             return true;
         }

PluralKit.Core/Database/Database.cs

@@ -37,7 +37,10 @@ namespace PluralKit.Core
             
             _connectionString = new NpgsqlConnectionStringBuilder(_config.Database)
             {
-                Pooling = true, MaxPoolSize = 500, Enlist = false, NoResetOnClose = true
+                Pooling = true, MaxPoolSize = 500, Enlist = false, NoResetOnClose = true,
+                
+                // Lower timeout than default (15s -> 2s), should ideally fail-fast instead of hanging
+                Timeout = 2
             }.ConnectionString;
         }