ci: use kaniko, registry host from secret, remove hardcoded values

.woodpecker.yml

@@ -3,16 +3,23 @@ when:
   event: push
 
 steps:
-  - name: login-and-push
-    image: docker:28-cli
-    environment:
-      REGISTRY_HOSTPORT:
+  - name: build-and-push
+    image: woodpeckerci/plugin-kaniko:2.1.1
+    settings:
+      registry:
         from_secret: REGISTRY_HOSTPORT
-      REGISTRY_USERNAME:
+      repo: nxtgauge-ai-assistant
+      dockerfile: Dockerfile
+      tags:
+        - ${CI_COMMIT_SHA}
+        - latest
+        - high-performance-latest
+      username:
         from_secret: REGISTRY_USERNAME
-      REGISTRY_PASSWORD:
+      password:
         from_secret: REGISTRY_PASSWORD
-    commands:
-      - echo "${REGISTRY_PASSWORD}" | docker login "${REGISTRY_HOSTPORT}" -u "${REGISTRY_USERNAME}" --password-stdin
-      - docker build -t "${REGISTRY_HOSTPORT}/nxtgauge-ai-assistant" -f Dockerfile .
-      - docker push "${REGISTRY_HOSTPORT}/nxtgauge-ai-assistant"
+      insecure: true
+      insecure_pull: true
+      skip_tls_verify: true
+      platforms: linux/amd64
+      cache: false