Refactor platform names in .woodpecker.yml

Changed the platform names from "linux/amd64" and "linux/arm64" to "amd64" and "arm64", respectively. Also updated the platform variable in pipeline tags to include the prefix "linux/".

.woodpecker.yml

@@ -1,7 +1,7 @@
 matrix:
   platform:
-    - linux/amd64
-    - linux/arm64
+    - amd64
+    - arm64
   os:
     - alpine
     - slim
@@ -10,7 +10,7 @@ matrix:
     - 18
     - 20
 
-platform: ${platform}
+platform: linux/${platform}
 
 pipeline:
   build:
@@ -19,7 +19,7 @@ pipeline:
       registry: techio.dev
       repo: techio.dev/${CI_REPO}
       tags:
-        - ${version}-${os}
+        - ${version}-${os}-${platform}
       build_args:
         - tag=${version}-${os}
       username: deploy