chore: revert #5069 to restore Netlify builds

`assetgraph-builder` is used through at least the `buildProduction` command

This reverts commit 53a4baf.

docs/_data/supporters.js

@@ -17,6 +17,7 @@
 
 'use strict';
 
+const {loadImage} = require('canvas');
 const {writeFile, mkdir, rm} = require('fs').promises;
 const {resolve} = require('path');
 const debug = require('debug')('mocha:docs:data:supporters');
@@ -114,6 +115,13 @@ const fetchImage = process.env.MOCHA_DOCS_SKIP_IMAGE_DOWNLOAD
           );
         }
         debug('fetched %s', url);
+        const canvasImage = await loadImage(imageBuf);
+        debug('ok %s', url);
+        supporter.dimensions = {
+          width: canvasImage.width,
+          height: canvasImage.height
+        };
+        // debug('dimensions %s %dw %dh', url, canvasImage.width, canvasImage.height);
         const filePath = resolve(SUPPORTER_IMAGE_PATH, supporter.id + '.png');
         await writeFile(filePath, imageBuf);
         debug('wrote %s', filePath);

docs/_includes/supporters.md

@@ -8,7 +8,7 @@ Use Mocha at Work? Ask your manager or marketing team if they'd help [support](h
     {%- if supporter.website -%}
     <a href="{{ supporter.website }}" target="_blank" rel="noopener">
     {%- endif -%}
-      <div class="sponsor" title="{{ supporter.name }}" style="background-image: url(/images/supporters/{{ supporter.id }}.png?sprite=sponsors)"></div>
+      <div class="sponsor" title="{{ supporter.name }}" style="width: {{ supporter.dimensions.width }}px; background-image: url(/images/supporters/{{ supporter.id }}.png?sprite=sponsors)"></div>
     {%- if supporter.website -%}
     </a>
     {%- endif -%}

docs/css/supporters.css

@@ -9,9 +9,6 @@
   -sprite-location: url(/images/sprite-backers.png?pngquant);
   -sprite-image-format: png;
   -sprite-padding: 0 10;
-  background-position: center;
-  background-repeat: no-repeat;
-  background-size: contain;
   width: 32px;
   height: 32px;
 }