Update flux-v1-automation-migration.md to replace deprecated/removed …

…--branch with --{checkout,push}-branch

Does what it says on the tin.

Signed-off-by: Tony DevOps <[email protected]>

content/en/flux/migration/flux-v1-automation-migration.md

@@ -286,7 +286,9 @@ $ # the environment variables $AUTO_PATH and $GIT_NAME are set above
 $ [email protected] # supply your own host or address here
 $ flux create image update my-app-auto \
     --author-name FluxBot --author-email "$FLUXBOT_EMAIL" \
-    --git-repo-ref $GIT_NAME --branch main \
+    --git-repo-ref $GIT_NAME \
+    --checkout-branch main \
+    --push-branch main \
     --interval 30m \
     --export > ./$AUTO_PATH/my-app-auto.yaml
 $ cat my-app-auto.yaml