nodejs: isArm -> isAarch32

This is the last package reference to isArm.  isArm is deprecated after 18.03.
This substitution was performed tree-wide in #37401.

pkgs/development/web/nodejs/nodejs.nix

@@ -61,18 +61,18 @@ in
     configureFlags = let
       isCross = stdenv.hostPlatform != stdenv.buildPlatform;
       host = stdenv.hostPlatform.platform;
-      isArm = stdenv.hostPlatform.isArm;
+      isAarch32 = stdenv.hostPlatform.isAarch32;
     in sharedConfigureFlags ++ [
       "--without-dtrace"
     ] ++ (optionals isCross [
       "--cross-compiling"
       "--without-intl"
       "--without-snapshot"
-    ]) ++ (optionals (isCross && isArm && hasAttr "fpu" host.gcc) [
+    ]) ++ (optionals (isCross && isAarch32 && hasAttr "fpu" host.gcc) [
       "--with-arm-fpu=${host.gcc.fpu}"
-    ]) ++ (optionals (isCross && isArm && hasAttr "float-abi" host.gcc) [
+    ]) ++ (optionals (isCross && isAarch32 && hasAttr "float-abi" host.gcc) [
       "--with-arm-float-abi=${host.gcc.float-abi}"
-    ]) ++ (optionals (isCross && isArm) [
+    ]) ++ (optionals (isCross && isAarch32) [
       "--dest-cpu=arm"
     ]) ++ extraConfigFlags;