loadSchema function cannot accept array of pointers in Typescript declaration files

### Which packages are impacted by your issue?

@graphql-codegen/cli

### Describe the bug

Function `loadSchema` should support array of pointers as an argument. The function support this behaviour, but the types are not.

https://github.com/dotansimha/graphql-code-generator/blob/b73ed8f18cf55d00640617f7bc5c33d5cfc88663/packages/graphql-codegen-cli/src/load.ts#L31

The same problem in method `loadSchema` in `CodegenContext` class. It should be Types.Schema[].
https://github.com/dotansimha/graphql-code-generator/blob/b73ed8f18cf55d00640617f7bc5c33d5cfc88663/packages/graphql-codegen-cli/src/config.ts#L425

`loadSchema` from `@graphql-tools/load` supports array of pointers too.

https://github.com/ardatan/graphql-tools/blob/66b6a98d7e134e932f28e7788b4884d2c0461b12/packages/load/src/schema.ts#L45

### Your Example Website or App

-

### Steps to Reproduce the Bug or Issue

`loadSchema(['src/schema-1.graphql', 'src/schema-2.graphql']` shows error

### Expected behavior

`loadSchema(['src/schema-1.graphql', 'src/schema-2.graphql']` don't show error

### Screenshots or Videos

_No response_

### Platform

- OS: [e.g. macOS, Windows, Linux]
- NodeJS: [e.g. 18.5.0]
- `graphql` version: [e.g. 16.3.0]
- `@graphql-codegen/*` version(s): [e.g. 2.6.2]

### Codegen Config File

_No response_

### Additional context

_No response_