fix: ensure floating popup windows are auto closed when they lose focus

Fixes #591

lua/neogit/lib/popup.lua

@@ -575,6 +575,19 @@ function M:show()
       }
     end,
   }
+
+  -- Closes the window if it loses focus and it is a floating buffer
+  if self.buffer.kind == "floating" then
+    vim.api.nvim_create_autocmd("WinLeave", {
+      callback = function(win)
+        if win.buf == self.buffer.handle then
+          -- We pcall this because it's possible the window was closed by a command invocation, e.g. "cc" for commits
+          pcall(self.close)
+        end
+      end,
+      once = true,
+    })
+  end
 end
 
 return M