fix(gatsby-plugin-utils): Make GatsbyImageData nullable (#35777) (#35785)

Co-authored-by: Lennart <[email protected]>

Author: gatsbybot

packages/gatsby-plugin-utils/src/polyfill-remote-file/graphql/gatsby-image-resolver.ts

@@ -261,7 +261,7 @@ export function generateGatsbyImageFieldConfig(
   IGatsbyImageDataArgs
 > {
   return {
-    type: hasFeature(`graphql-typegen`) ? `GatsbyImageData!` : `JSON`,
+    type: hasFeature(`graphql-typegen`) ? `GatsbyImageData` : `JSON`,
     description: `Data used in the <GatsbyImage /> component. See https://gatsby.dev/img for more info.`,
     args: {
       layout: {

packages/gatsby/src/schema/__tests__/__snapshots__/print.js.snap

@@ -193,7 +193,7 @@ interface RemoteFile {
     fit: RemoteFileFit = COVER
     cropFocus: [RemoteFileCropFocus]
     quality: Int = 75
-  ): GatsbyImageData!
+  ): GatsbyImageData
 }
 
 type File implements Node @dontInfer {
@@ -582,7 +582,7 @@ interface RemoteFile {
     fit: RemoteFileFit = COVER
     cropFocus: [RemoteFileCropFocus]
     quality: Int = 75
-  ): GatsbyImageData!
+  ): GatsbyImageData
 }
 
 type File implements Node @dontInfer {
@@ -981,7 +981,7 @@ interface RemoteFile {
     fit: RemoteFileFit = COVER
     cropFocus: [RemoteFileCropFocus]
     quality: Int = 75
-  ): GatsbyImageData!
+  ): GatsbyImageData
 }
 
 type File implements Node @dontInfer {