Bump alpine from 3.19 to 3.20 in /build (#2019)

Bumps alpine from 3.19 to 3.20.

---
updated-dependencies:
- dependency-name: alpine
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

build/Dockerfile

@@ -11,7 +11,7 @@ RUN make build
 
 FROM golang:1.22 as ca-certs-provider
 
-FROM alpine:3.19 as capabilizer
+FROM alpine:3.20 as capabilizer
 RUN apk add --no-cache libcap
 
 FROM capabilizer as local-capabilizer

build/Dockerfile.nginxplus

@@ -5,7 +5,7 @@ FROM scratch as nginx-files
 ADD --link --chown=101:1001 https://cs.nginx.com/static/keys/nginx_signing.rsa.pub nginx_signing.rsa.pub
 
 
-FROM alpine:3.19
+FROM alpine:3.20
 
 ARG NGINX_PLUS_VERSION=R32
 ARG NJS_DIR