Bump alpine from 3.14 to 3.18 in /protobuf (#174)

Bumps alpine from 3.14 to 3.18.

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

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

protobuf/Dockerfile

@@ -15,7 +15,7 @@ ARG UPX_VERSION=4.0.2
 
 ARG TARGETARCH=amd64
 
-FROM alpine:3.14 as protoc_builder
+FROM alpine:3.18 as protoc_builder
 RUN apk add --no-cache build-base curl automake autoconf libtool git zlib-dev linux-headers cmake ninja
 
 RUN mkdir -p /out
@@ -130,7 +130,7 @@ RUN mkdir -p ${GOPATH}/src/github.com/atoulme/protoc-gen-parquet && \
     mkdir -p /out/usr/include/protoc-gen-parquet/options && \
     install -D $(find ./parquet_options -name '*.proto') -t /out/usr/include/protoc-gen-parquet/options
 
-FROM alpine:3.14 as packer
+FROM alpine:3.18 as packer
 RUN apk add --no-cache curl
 
 ARG UPX_VERSION
@@ -156,7 +156,7 @@ RUN upx --lzma $(find /out/usr/bin/ \
 RUN find /out -name "*.a" -delete -or -name "*.la" -delete
 
 
-FROM alpine:3.14
+FROM alpine:3.18
 LABEL maintainer="The OpenTelemetry Authors"
 COPY --from=packer /out/ /
 RUN apk add --no-cache bash libstdc++ && \