trigger build when docker folder changes

Author: Tiaansu

.github/workflows/build.yml

@@ -13,6 +13,7 @@ on:
       - "**.h"
       - "**.c"
       - ".github/workflows/build.yml"
+      - "docker"
   pull_request:
     branches:
       - "*"
@@ -24,6 +25,7 @@ on:
       - "**.h"
       - "**.c"
       - ".github/workflows/build.yml"
+      - "docker"
 
 jobs:
   build-windows-release: