Use latest base images. (#1334)

* Use latest images.

* Fix version

Dockerfile

@@ -1,10 +1,10 @@
-FROM golang:1.19 AS build
+FROM golang:1.21 AS build
 WORKDIR /go/src/github.com/zricethezav/gitleaks
 COPY . .
 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
+FROM alpine:3.19
 RUN apk add --no-cache bash git openssh-client
 COPY --from=build /go/src/github.com/zricethezav/gitleaks/bin/* /usr/bin/