fix(health): "q" keymap not set when health.style=float #37007

Problem:
The q keymap is already set in open_floating_preview, so maparg('q') is not empty.

Solution:
Add a health.style check before setting the q keymap.

test/functional/plugin/health_spec.lua

@@ -88,6 +88,7 @@ describe(':checkhealth', function()
       return vim.api.nvim_win_get_config(0).relative
     ]])
     )
+    matches('health%.lua:%d+>$', fn.maparg('q', 'n', false, false))
 
     -- gO should not close the :checkhealth floating window. #34784
     command('checkhealth full_render')