ci: fix runner labels (hanzo-build pool + ubuntu-24.04-arm native)

Imaginary runner labels `lux-build-linux-amd64` / `lux-build-linux-arm64`
do not exist. The live amd64 pool is `hanzo-build-linux-amd64`; native
arm64 builds run on GitHub-hosted `ubuntu-24.04-arm`.

- release-binaries.yml: create-release + matrix linux/amd64 + matrix linux/arm64
- publish_docker.yml: build-amd64

.github/workflows/publish_docker.yml

@@ -17,7 +17,7 @@ permissions:
 
 jobs:
   build-amd64:
-    runs-on: lux-build-linux-amd64
+    runs-on: hanzo-build-linux-amd64
     outputs:
       digest: ${{ steps.build.outputs.digest }}
     steps:

.github/workflows/release-binaries.yml

@@ -9,7 +9,7 @@ permissions:
 
 jobs:
   create-release:
-    runs-on: lux-build-linux-amd64
+    runs-on: hanzo-build-linux-amd64
     outputs:
       upload_url: ${{ steps.release.outputs.upload_url }}
     steps:
@@ -30,10 +30,10 @@ jobs:
         include:
           - os: linux
             arch: amd64
-            runner: lux-build-linux-amd64
+            runner: hanzo-build-linux-amd64
           - os: linux
             arch: arm64
-            runner: lux-build-linux-arm64
+            runner: ubuntu-24.04-arm
           - os: darwin
             arch: amd64
             runner: macos-13