fix: add missing type for 'expirationChecker' on PgConnectionConfig (knex#5334)

Co-authored-by: Igor Savin <[email protected]>

Author: sam-super

test-tsd/pg-config.test-d.ts

@@ -0,0 +1,28 @@
+import { expectAssignable } from 'tsd';
+
+import {Knex} from '../types';
+import * as stream from "stream";
+
+expectAssignable<Knex.PgConnectionConfig>({
+  user: '',
+  database: '',
+  password: '',
+  port: 1,
+  host: '',
+  connectionString: '',
+  keepAlive: true,
+  stream: new stream.Duplex(),
+  statement_timeout: false,
+  parseInputDatesAsUTC: false,
+  ssl: true,
+  query_timeout: 2,
+  keepAliveInitialDelayMillis: 3,
+  idle_in_transaction_session_timeout: 4,
+  application_name: '',
+  connectionTimeoutMillis: 5,
+  types: {
+    getTypeParser: () => {},
+  },
+  options: '',
+  expirationChecker: () => {return true;},
+});

types/index.d.ts

@@ -3025,6 +3025,7 @@ export declare namespace Knex {
     connectionTimeoutMillis?: number;
     types?: PgCustomTypesConfig;
     options?: string;
+    expirationChecker?(): boolean;
   }
 
   type PgGetTypeParser = (oid: number, format: string) => any;