remove duplicate template (#5016)

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,17 +0,0 @@
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-name: Feature request
-about: Suggest an idea for this project
-
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.