fix(RELEASE-1174): leftover comments for pr #559 (#597)

this commit addresses leftover comments of the PR #559.

1. remove one skopeo call to get image metadata and
  and also save some task time.
2. remove oras from mock.sh - this one was previously
  done in a rebase of #559.

Signed-off-by: Leandro Mendes <[email protected]>

tasks/get-ocp-version/get-ocp-version.yaml

@@ -28,8 +28,12 @@ spec:
 
         fbc_fragment="$(params.fbcFragment)"
 
-        # get the media type
-        media_type=$(skopeo inspect --raw "docker://${fbc_fragment}" | jq -r .mediaType)
+        # get image metadata
+        image_metadata=$(skopeo inspect --raw "docker://${fbc_fragment}")
+
+        media_type=$(jq -r .mediaType <<< "${image_metadata}")
+        image_base_name=$(jq '.annotations."org.opencontainers.image.base.name"' <<< "${image_metadata}" \
+          | cut -d: -f2 | sed 's/"//g')
 
         # multiplatform images will not contain the base name with the OCP version, so it should fetch
         # the manifest image
@@ -41,16 +45,11 @@ spec:
           manifest_image_sha="$(jq -rs 'map(.digest)[0]'  <<< "$arch_json")"
 
           # replace the image sha with the manifests's one
-          manifest_image="${fbc_fragment%@*}@${manifest_image_sha}"
+          fbc_fragment="${fbc_fragment%@*}@${manifest_image_sha}"
 
           # fetch the image base name containing the version for the found manifest image
-          image_base_name=$(skopeo inspect --raw docker://"${manifest_image}" \
-           | jq '.annotations."org.opencontainers.image.base.name"' | cut -d: -f2 | sed 's/"//g')
-
-        else
-          # fetch the image base name containing the version for a manifest image
           image_base_name=$(skopeo inspect --raw docker://"${fbc_fragment}" \
-          | jq '.annotations."org.opencontainers.image.base.name"' | cut -d: -f2 | sed 's/"//g')
+           | jq '.annotations."org.opencontainers.image.base.name"' | cut -d: -f2 | sed 's/"//g')
         fi
 
         # Define the regular expression