GHA package.yaml: Job label/name to 'jpackage'

* Change job label from `build` to `jpackage`
* Add a `name` attribute setting name with matrix.os

This matches the format of `nix-jpackage.yaml` in PR sparrowwallet#1648
to keep them similar assuming it is merged as is.

Author: msgilligan

.github/workflows/package.yaml

@@ -6,7 +6,8 @@ permissions:
   contents: read
 
 jobs:
-  build:
+  jpackage:
+    name: jpackage ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -53,4 +54,4 @@ jobs:
           name: Sparrow Build - ${{ runner.os }} ${{ runner.arch }} Headless
           path: |
             build/jpackage/*
-            !build/jpackage/Sparrow/
+            !build/jpackage/Sparrow/