fix: reduce warnings about density values > 2

resolves #1308

Author: danielroe

src/runtime/utils/index.ts

@@ -113,7 +113,11 @@ export function checkDensities(densities: number[]) {
     throw new Error('`densities` must not be empty, configure to `1` to render regular size only (DPR 1.0)')
   }
   if (import.meta.dev && Array.from(densities).some(d => d > 2)) {
-    console.warn('[nuxt] [image] Density values above `2` are not recommended. See https://observablehq.com/@eeeps/visual-acuity-and-device-pixel-ratio.')
+    const _densities = densities as number[] & { _warned?: boolean }
+    if (!_densities._warned) {
+      console.warn('[nuxt] [image] Density values above `2` are not recommended. See https://observablehq.com/@eeeps/visual-acuity-and-device-pixel-ratio.')
+    }
+    _densities._warned = true
   }
 }