Revert "Query runtime version of LLVM"

This reverts commit c43bac2.

src/llvm.cr

@@ -4,18 +4,9 @@ require "c/string"
 module LLVM
   @@initialized = false
 
-  # Returns the runtime version of LLVM.
-  #
-  # NOTE: Prior to LLVM 16.0 this method returns the compile time version, i.e.
-  # which as linked against. It might be different from the actually loaded
-  # version at runtime.
+  # Returns the version of LLVM.
   def self.version
-    {% if LibLLVM.has_method?(:get_version) %}
-      LibLLVM.get_version(out major, out minor, out patch)
-      "#{major}.#{minor}.#{patch}"
-    {% else %}
-      LibLLVM::VERSION
-    {% end %}
+    LibLLVM::VERSION
   end
 
   def self.init_x86 : Nil

src/llvm/lib_llvm/core.cr

@@ -17,10 +17,6 @@ lib LibLLVM
 
   fun dispose_message = LLVMDisposeMessage(message : Char*)
 
-  {% unless LibLLVM::IS_LT_160 %}
-    fun get_version = LLVMGetVersion(major : UInt*, minor : UInt*, patch : UInt*) : Void
-  {% end %}
-
   fun create_context = LLVMContextCreate : ContextRef
   fun dispose_context = LLVMContextDispose(c : ContextRef)