build v2.11.2 for node 21

Author: zbjornson

.github/workflows/prebuild.yaml

@@ -50,7 +50,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node: [20]
+        node: [21]
         canvas_tag: ["v2.11.2"] # e.g. "v2.6.1"
     name: ${{ matrix.canvas_tag }}, Node.js ${{ matrix.node }}, Linux
     runs-on: ubuntu-latest
@@ -143,7 +143,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node: [20]
+        node: [21]
         canvas_tag: ["v2.11.2"] # e.g. "v2.6.1"
     name: ${{ matrix.canvas_tag}}, Node.js ${{ matrix.node }}, macOS
     runs-on: macos-latest
@@ -216,7 +216,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node: [20]
+        node: [21]
         canvas_tag: ["v2.11.2"] # e.g. "v2.6.1"
     name: ${{ matrix.canvas_tag}}, Node.js ${{ matrix.node }}, Windows
     runs-on: windows-2019