Remove the limit used to decided if a group canvas must be upscaled or not

It fixes issues #14982 and #14724.
The main problem of upscaling a canvas is that it can induces some pixelation
(see issue #14724). So this patch is just removing the limit and as a side
effect it fixes issue #14982.
As far as I can tell, in looking different profiles (especially some memory profile)
in using the Firefox profiler, I don't see any noticeable difference in term of
memory use.

test/pdfs/issue14724.pdf.link

@@ -0,0 +1,2 @@
+https://github.com/mozilla/pdf.js/files/8365628/Infographic_EAP_EN_v2.1.pdf
+

test/pdfs/issue14982.pdf.link

@@ -0,0 +1,2 @@
+https://github.com/mozilla/pdf.js/files/8829368/Tillamook-Market-Menu-04.04.22.pdf
+

test/test_manifest.json

@@ -9965,5 +9965,21 @@
     "rounds": 1,
     "link": true,
     "type": "eq"
+  },
+  {
+    "id": "issue14724",
+    "file": "pdfs/issue14724.pdf",
+    "md5": "34ecf91792eb54d58e0e86f877017f71",
+    "rounds": 1,
+    "link": true,
+    "type": "eq"
+  },
+  {
+    "id": "issue14982",
+    "file": "pdfs/issue14982.pdf",
+    "md5": "bbd7d7f75f51a477b56b6e3f69174d06",
+    "rounds": 1,
+    "link": true,
+    "type": "eq"
   }
 ]