refactor: Remove RDS parameter group code

Since aws/aws-cdk#18126, this exact logic is handled by aws-cdk.

src/constructs/rds/instance.test.ts

@@ -75,7 +75,7 @@ describe("The GuDatabaseInstance class", () => {
 
     expect(stack).toHaveResource("AWS::RDS::DBInstance", {
       DBParameterGroupName: {
-        Ref: "DatabaseInstanceRDSParameterGroup307734CB",
+        Ref: "DatabaseInstanceTestingParameterGroup0F38B815",
       },
     });
 

src/constructs/rds/instance.ts

@@ -1,19 +1,18 @@
 import { InstanceType } from "@aws-cdk/aws-ec2";
-import { DatabaseInstance, ParameterGroup } from "@aws-cdk/aws-rds";
-import type { DatabaseInstanceProps, IParameterGroup } from "@aws-cdk/aws-rds";
+import { DatabaseInstance } from "@aws-cdk/aws-rds";
+import type { DatabaseInstanceProps } from "@aws-cdk/aws-rds";
 import { Fn } from "@aws-cdk/core";
 import { GuStatefulMigratableConstruct } from "../../utils/mixin";
 import { GuAppAwareConstruct } from "../../utils/mixin/app-aware-construct";
 import type { GuStack } from "../core";
-import { AppIdentity } from "../core/identity";
+import type { AppIdentity } from "../core/identity";
 import type { GuMigratingResource } from "../core/migrating";
 
 export interface GuDatabaseInstanceProps
   extends Omit<DatabaseInstanceProps, "instanceType">,
     AppIdentity,
     GuMigratingResource {
   instanceType: string;
-  parameters?: Record<string, string>;
 }
 
 export class GuDatabaseInstance extends GuStatefulMigratableConstruct(GuAppAwareConstruct(DatabaseInstance)) {
@@ -23,23 +22,10 @@ export class GuDatabaseInstance extends GuStatefulMigratableConstruct(GuAppAware
     // This logic ensures the "db." prefix is removed before applying the CFN
     const instanceType = new InstanceType(Fn.join("", Fn.split("db.", props.instanceType)));
 
-    let parameterGroup: IParameterGroup | undefined;
-    if (props.parameterGroup) {
-      parameterGroup = props.parameterGroup;
-    } else if (props.parameters) {
-      parameterGroup = new ParameterGroup(scope, `${id}-RDSParameterGroup`, {
-        engine: props.engine,
-        parameters: props.parameters,
-      });
-    }
-
     super(scope, id, {
       deletionProtection: true,
       ...props,
       instanceType,
-      ...(parameterGroup && { parameterGroup }),
     });
-
-    parameterGroup && AppIdentity.taggedConstruct(props, parameterGroup);
   }
 }