chore: fixes, converting to docker action

Dockerfile

@@ -1,13 +1,9 @@
 FROM golang:1.24-alpine AS build
-RUN useradd -m appuser
-USER appuser
 WORKDIR /app
 COPY . .
 RUN go build -o /go-test-sarif ./cmd/main.go
 
 FROM alpine:3.21.3
-RUN useradd -m appuser
-USER appuser
 COPY --from=build /go-test-sarif /go-test-sarif
 COPY action/entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh

action.yml

@@ -1,6 +1,11 @@
 name: 'Go Test to SARIF Converter'
 description: 'Converts Go test JSON output to SARIF format.'
+
 author: 'Ismo Vuorinen'
+branding:
+  icon: "check"
+  color: "green"
+
 inputs:
   input_file:
     description: 'Path to the Go test JSON results file.'
@@ -8,11 +13,10 @@ inputs:
   output_file:
     description: 'Path where the SARIF output should be saved.'
     required: true
+
 runs:
-  using: 'composite'
-  steps:
-    - name: Convert Go test results to SARIF
-      uses: ivuorinen/go-test-sarif-action@58ffaaacdb178a5d053f8e8c2693966422a3ecda # v1
-      with:
-        input_file: ${{ inputs.input_file }}
-        output_file: ${{ inputs.output_file }}
+  using: "docker"
+  image: "docker://ivuorinen/go-test-sarif-action:v1"
+  with:
+    input_file: ${{ inputs.input_file }}
+    output_file: ${{ inputs.output_file }}