Set a fixed version number for api_version

Author: m-mohr

openapi.yaml

@@ -550,7 +550,8 @@ paths:
                     description: >-
                       Version number of the openEO specification this back-end
                       implements.
-                    example: 1.0.1
+                    enum:
+                      - 1.0.0
                   backend_version:
                     type: string
                     description: >-
@@ -895,7 +896,6 @@ paths:
                           description: >-
                             Version number of the openEO specification this
                             back-end implements.
-                          example: 1.0.1
               example:
                 versions:
                   - url: 'https://example.openeo.org/api/v0.5'