ci: enable armhf build test

Signed-off-by: Kentaro Hayashi <hayashi@clear-code.com>

Author: kenhys

.github/workflows/linux.yml

@@ -16,6 +16,7 @@ jobs:
         include:
           - dockerfile: v1.19/debian
           - dockerfile: v1.19/arm64/debian
+          - dockerfile: v1.19/armhf/debian
     runs-on: >-
       ${{ (contains(matrix.dockerfile, 'arm64')) && 'ubuntu-24.04-arm' || 'ubuntu-latest' }}
     steps: