Remove unneeded quotes
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 54a80aa..86dfe4c 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -8,7 +8,7 @@
 
 env:
   LIBYAML_REPO: https://github.com/yaml/libyaml
-  LIBYAML_REF: '0.2.5'
+  LIBYAML_REF: 0.2.5
 
 jobs:
   python_sdist: