CI: update runner labels for self-hosted runners

It was suggested in code review for another project that we update the
runner labels for clarity.  This brings Packager in line with that, so
that we are using the same labels across projects.

The runners have already been updated to register with the new label.

Change-Id: I30b22530225b5bd22b965ba98d276bcd74ade6cf

.github/workflows/build_and_test.yaml

@@ -38,7 +38,7 @@ jobs:
     needs: lint
     strategy:
       matrix:
-        os: ["ubuntu-latest", "macos-latest", "windows-latest", "linux-arm64"]
+        os: ["ubuntu-latest", "macos-latest", "windows-latest", "self-hosted-linux-arm64"]
         build_type: ["Debug", "Release"]
         lib_type: ["static", "shared"]
         include:
@@ -58,7 +58,7 @@ jobs:
             exe_ext: ".exe"
             # 64-bit outputs on Windows go to a different folder name.
             build_type_suffix: "_x64"
-          - os: linux-arm64
+          - os: self-hosted-linux-arm64
             os_name: linux
             target_arch: arm64
             exe_ext: ""

.github/workflows/github_release.yaml

@@ -112,7 +112,7 @@ jobs:
     needs: [setup, lint, draft_release]
     strategy:
       matrix:
-        os: ["ubuntu-latest", "macos-latest", "windows-latest", "linux-arm64"]
+        os: ["ubuntu-latest", "macos-latest", "windows-latest", "self-hosted-linux-arm64"]
         build_type: ["Debug", "Release"]
         lib_type: ["static", "shared"]
         include:
@@ -132,7 +132,7 @@ jobs:
             exe_ext: ".exe"
             # 64-bit outputs on Windows go to a different folder name.
             build_type_suffix: "_x64"
-          - os: linux-arm64
+          - os: self-hosted-linux-arm64
             os_name: linux
             target_arch: arm64
             exe_ext: ""