Remove Drupal 8.7 compat and Be totally Drupal 9.0 compliant

And since we depend on webform, let's use the version that Drupal 9 loves too
5.19

composer.json

@@ -13,11 +13,11 @@
         }
     ],
     "require": {
-        "ml/json-ld": "^1.1",
+        "ml/json-ld": "^1.2",
         "mtdowling/jmespath.php":"^2.5",
         "strawberryfield/strawberryfield":"dev-8.x-1.0-beta3",
         "strawberryfield/format_strawberryfield":"dev-8.x-1.0-beta3",
-        "drupal/webform": "^5.9",
+        "drupal/webform": "^5.19",
         "drupal/webform_views": "^5.0"
     }
 }

webform_strawberryfield.info.yml

@@ -2,12 +2,11 @@ name: Strawberry Field Webform Integration
 description: Provides Webform integrations to feed a field of Strawberries.
 package: Archipelago
 type: module
-core: 8.x
+core_version_requirement: ^8.8 || ^9
 php: 7.1
 dependencies:
   - 'drupal:field'
   - 'drupal:file'
-  - 'drupal:system (>= 8.7)'
   - 'drupal:user'
   - 'strawberryfield'
-  - 'webform:webform (>= 8.x-5.3)'
+  - 'webform:webform (>= 8.x-5.19)'

webform_strawberryfield.module

@@ -340,20 +340,12 @@ function webform_strawberryfield_preprocess_webform_element_image_file(
         $iiifserversettings->get('pub_server_url'),
         $iiifserversettings->get('int_server_url')
       );
-      // Deal with Drupal 8.8.x v/s 8.7
-      if (method_exists(
-        \Drupal::service('stream_wrapper_manager'),
-        'getTarget'
-      )) {
-        $iiifidentifier = urlencode(
-          \Drupal::service('stream_wrapper_manager')->getTarget(
+      // Deal with Drupal 8.8.x only now
+      $iiifidentifier = urlencode(
+        \Drupal::service('stream_wrapper_manager')->getTarget(
             $file->getFileUri()
-          )
-        );
-      }
-      else {
-        $iiifidentifier = urlencode(file_uri_target($file->getFileUri()));
-      }
+        )
+      );
 
       if ($iiifidentifier == NULL || empty($iiifidentifier)) {
         // Nothing to do, lets leave this untouched.