Bump golang verion used in docker build to match version specified in go.mod (#1551)

Signed-off-by: Jannik Hollenbach <jannik.hollenbach@owasp.org>

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.21 AS build
+FROM golang:1.22 AS build
 WORKDIR /go/src/github.com/zricethezav/gitleaks
 COPY . .
 RUN VERSION=$(git describe --tags --abbrev=0) && \