typeorm: Adding an enum field does not generate a migration

Issue Description

When I add an enum item to an existing enum field on an Entity and run migration:generate, a blank migration is created

Expected Behavior

I expect a migration to be created to add add the field to the Postgres database

Actual Behavior

An empty migration is created

Steps to Reproduce

1. Add an entity with an enum field:

export enum Status {
  Live = 'live',
  Draft = 'draft',
  Archived = 'archived',
}

@Entity({ name: 'something' })
export class Something {

  @Column({
    type: 'enum',
    enum: Status,
    default: Status.Draft,
  })
  status: OrganisationVersionStatus;
}

1. Generate and run the migrations
2. Add another enum field:

export enum Status {
  Live = 'live',
  Draft = 'draft',
  Archived = 'archived',
  Unconfirmed = 'unconfirmed',
}

@Entity({ name: 'something' })
export class Something {

  @Column({
    type: 'enum',
    enum: Status,
    default: Status.Draft,
  })
  status: OrganisationVersionStatus;
}

1. Generate the migrations
2. Result:

export class AddUnconfirmedStatusToSomething643119746947 implements MigrationInterface
{
  name = 'AddUnconfirmedStatusToSomething1643119746947';

  public async up(queryRunner: QueryRunner): Promise<void> {}

  public async down(queryRunner: QueryRunner): Promise<void> {}
}

My Environment

Dependency	Version
Operating System	Mac OS
Node.js version	16.13.0
Typescript version	4.4.4
TypeORM version	0.2.40

Additional Context

Relevant Database Driver(s)

DB Type	Reproducible
aurora-data-api	no
aurora-data-api-pg	no
better-sqlite3	no
cockroachdb	no
cordova	no
expo	no
mongodb	no
mysql	no
nativescript	no
oracle	no
postgres	yes
react-native	no
sap	no
sqlite	no
sqlite-abstract	no
sqljs	no
sqlserver	no

Are you willing to resolve this issue by submitting a Pull Request?

• ✖️ Yes, I have the time, and I know how to start.
• ✖️ Yes, I have the time, but I don’t know how to start. I would need guidance.
• ✖️ No, I don’t have the time, but I can support (using donations) development.
• ✅ No, I don’t have the time and I’m okay to wait for the community / maintainers to resolve this issue.