fix(ci): add missing 'v' in tag

Author: jeertmans

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- start changelog -->
 
 (unreleased)=
-## [Unreleased](https://github.com/jeertmans/manim-slides/compare/5.1.7...HEAD)
+## [Unreleased](https://github.com/jeertmans/manim-slides/compare/v5.1.7...HEAD)
 
 (unreleased-chore)=
 ### Chore

pyproject.toml

@@ -114,7 +114,7 @@ filename = "CHANGELOG.md"
 replace = '''<!-- start changelog -->
 
 (unreleased)=
-## [Unreleased](https://github.com/jeertmans/manim-slides/compare/{new_version}...HEAD)'''
+## [Unreleased](https://github.com/jeertmans/manim-slides/compare/v{new_version}...HEAD)'''
 search = "<!-- start changelog -->"
 
 [tool.codespell]