build: bump alpine from 3.20.2 to 3.20.3

Bumps alpine from 3.20.2 to 3.20.3.

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

Signed-off-by: dependabot[bot] <[email protected]>

Dockerfile.alpine

@@ -26,7 +26,7 @@ RUN set -eu; \
 	go build -ldflags "-X main.buildVersion=${FOREGO_VERSION}" -o forego .; \
 	go clean -cache
 
-FROM --platform=$TARGETPLATFORM alpine:3.20.2
+FROM --platform=$TARGETPLATFORM alpine:3.20.3
 
 ARG FOREGO_VERSION
 ENV FOREGO_VERSION=${FOREGO_VERSION}