ci: Add shorter names to CI jobs

By default GitHub lists all arguments in brackets after job name.
This gets unwieldy when we include runner labels in
#2037. For example, Linux job is now
"build-and-test (self-hosted, Linux, X64, stable)".
Shorten it to "build-and-test (linux, stable)" instead.

.github/workflows/continuous-integration.yml

@@ -15,15 +15,14 @@ jobs:
 
     strategy:
       matrix:
-        os:
-          - [self-hosted, Linux, X64]
-          - [self-hosted, macOS, ARM64]
-        rust_channel:
-          - stable
         include:
+          - os: [self-hosted, Linux, X64]
+            name: linux
           - os: [self-hosted, macOS, ARM64]
+            name: macos
             continue-on-error: true
 
+    name: build-and-test (${{ matrix.name }}, stable)
     runs-on: ${{ matrix.os }}
     # The `== true` makes it work wether continue-on-error has been defined or not.
     continue-on-error: ${{ matrix.continue-on-error == true }}