Enabling @deprecated at runtime leads to validation failure

### What happened?

I wanted to have a hook on `@deprecated` directive at runtime. So I added `skip_runtime: false` option for this directive. This led to error during validation:

```
validation failed: packages.Load: graph/generated.go:661:21: ec.directives.Deprecated undefined (type DirectiveRoot has no field or method Deprecated)
graph/generated.go:664:25: ec.directives.Deprecated undefined (type DirectiveRoot has no field or method Deprecated)

exit status 1
```

### What did you expect?

It was expected `Deprecated` field to be generated in `DirectiveRoot` structure, but it was filtered out by [`func (d *Data) Directives() [DirectiveList`](https://github.com/99designs/gqlgen/blob/master/codegen/data.go#L67).

### Minimal graphql.schema and models to reproduce

I've used steps from [Getting Started](https://gqlgen.com/getting-started/) for reproduction but with the following changes:

#### gqlgen.yml
```yaml
# Where are all the schema files located? globs are supported eg src/**/*.graphqls
schema:
- graph/*.graphqls

# Where should the generated server code go?
exec:
filename: graph/generated.go
package: graph

# Uncomment to enable federation
# federation:
# filename: graph/federation.go
# package: graph

directives:
deprecated:
skip_runtime: false

# Where should any generated models go?
model:
filename: graph/model/models_gen.go
package: model

# Where should the resolver implementations go?
resolver:
layout: follow-schema
dir: graph
package: graph

# Optional: turn on use ` + "`" + `gqlgen:"fieldName"` + "`" + ` tags in your models
# struct_tag: json

# Optional: turn on to use []Thing instead of []*Thing
# omit_slice_element_pointers: false

# Optional: turn off to make struct-type struct fields not use pointers
# e.g. type Thing struct { FieldA OtherThing } instead of { FieldA *OtherThing }
# struct_fields_always_pointers: true

# Optional: turn off to make resolvers return values instead of pointers for structs
# resolvers_always_return_pointers: true

# Optional: set to speed up generation time by not performing a final validation pass.
# skip_validation: true

# gqlgen will search for any type names in the schema in these go packages
# if they match it will use them, otherwise it will generate them.
autobind:
# - "test/graph/model"

# This section declares type mapping between the GraphQL and go type systems
#
# The first line in each type will be used as defaults for resolver arguments and
# modelgen, the others will be allowed when binding to fields. Configure them to
# your liking
models:
ID:
model:
- github.com/99designs/gqlgen/graphql.ID
- github.com/99designs/gqlgen/graphql.Int
- github.com/99designs/gqlgen/graphql.Int64
- github.com/99designs/gqlgen/graphql.Int32
Int:
model:
- github.com/99designs/gqlgen/graphql.Int
- github.com/99designs/gqlgen/graphql.Int64
- github.com/99designs/gqlgen/graphql.Int32
```

#### graph/schema.graphqls
```
# GraphQL schema example
#
# https://gqlgen.com/getting-started/

type Todo {
id: ID!
text: String!
done: Boolean! @deprecated(reason: "for test")
user: User!
}

type User {
id: ID!# GraphQL schema example
#
# https://gqlgen.com/getting-started/

type Todo {
id: ID!
text: String!
done: Boolean! @deprecated(reason: "for test")
user: User!
}

type User {
id: ID!
name: String!
}

type Query {
todos: [Todo!]!
}

input NewTodo {
text: String!
userId: String!
}

type Mutation {
createTodo(input: NewTodo!): Todo!
}

name: String!
}

type Query {
todos: [Todo!]!
}

input NewTodo {
text: String!
userId: String!
}

type Mutation {
createTodo(input: NewTodo!): Todo!
}
```

### versions
- `go run github.com/99designs/gqlgen version` v0.17.25
- `go version` go1.19.5 darwin/arm64