fix(process): close check handles (#1995)

Author: mirekdlugosz

lua/mason-core/installer/InstallHandle.lua

@@ -173,6 +173,7 @@ function InstallHandle:terminate()
             end
         end
         check:stop()
+        check:close()
         if not self:is_closed() then
             self:close()
         end

lua/mason-core/process.lua

@@ -215,6 +215,7 @@ function M.spawn(cmd, opts, callback)
                 end
             end
             check:stop()
+            check:close()
             callback(successful, exit_code, signal)
         end)