fix: don't die on missing optional dependency gifencoder

source/app/metrics/utils.mjs

@@ -764,6 +764,7 @@ export async function gif({page, width, height, frames, x = 0, y = 0, repeat = t
   if (fss.existsSync(path))
     await fs.unlink(path)
   //Create encoder
+  try {
     const GIFEncoder = (await import("gifencoder")).default
     const encoder = new GIFEncoder(width, height)
     encoder.createWriteStream().pipe(fss.createWriteStream(path))
@@ -784,6 +785,11 @@ export async function gif({page, width, height, frames, x = 0, y = 0, repeat = t
     const result = await fs.readFile(path, "base64")
     await fs.unlink(path)
     return `data:image/gif;base64,${result}`
+  }
+  catch (error) {
+    console.debug(`metrics/puppeteergif > could not create gif: ${error}`)
+    return "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mOcOnfpfwAGfgLYttYINwAAAABJRU5ErkJggg=="
+  }
 }
 
 /**D3 node wrapper (loosely based on https://github.com/d3-node/d3-node)*/