YAML: Apply trailingComma option (#9665)

changelog_unreleased/yaml/pr-9665.md

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+#### Apply `trailingComma` option (#9665 by @fisker)
+
+When `--trailing-comma=none`, should not add trailing comma to flowMapping and flowSequence.
+
+<!-- prettier-ignore -->
+```yaml
+# Input
+flow-mapping:
+  {
+    "object-does-not-fit-within-print-width": "------",
+    "TEST": "comma IS added here"
+  }
+flow-sequence:
+  [
+    "object-does-not-fit-within-print-width", "------",
+    "TEST", "comma IS added here"
+  ]
+
+# Prettier stable
+mapping:
+  {
+    "object-does-not-fit-within-print-width": "------",
+    "TEST": "comma IS added here",
+  }
+flow-sequence:
+  [
+    "object-does-not-fit-within-print-width",
+    "------",
+    "TEST",
+    "comma IS added here",
+  ]
+
+# Prettier master
+flow-mapping:
+  {
+    "object-does-not-fit-within-print-width": "------",
+    "TEST": "comma IS added here"
+  }
+flow-sequence:
+  [
+    "object-does-not-fit-within-print-width",
+    "------",
+    "TEST",
+    "comma IS added here"
+  ]
+```