removed gitleaks user from Dockerfile (#1313)

Dockerfile

@@ -5,10 +5,8 @@ RUN VERSION=$(git describe --tags --abbrev=0) && \
 CGO_ENABLED=0 go build -o bin/gitleaks -ldflags "-X="github.com/zricethezav/gitleaks/v8/cmd.Version=${VERSION}
 
 FROM alpine:3.16
-RUN adduser -D gitleaks && \
-    apk add --no-cache bash git openssh-client
+RUN apk add --no-cache bash git openssh-client
 COPY --from=build /go/src/github.com/zricethezav/gitleaks/bin/* /usr/bin/
-USER gitleaks
 
 RUN git config --global --add safe.directory '*'