Revert "ARMでもAMD64でも使えるDockerfileに"

This reverts commit 679e657.
すでにmatrixでarm64指定されていたのでOK

Dockerfile

@@ -5,22 +5,11 @@ ARG OYAKI_VERSION
 WORKDIR /go/src/oyaki
 COPY . /go/src/oyaki
 
-ARG TARGETARCH
-ENV LIBWEBP_VERSION=1.3.1
-ENV BASE_URL=https://storage.googleapis.com/downloads.webmproject.org/releases/webp
-RUN apt-get update && apt-get install -y curl tar
-RUN if [ "${TARGETARCH}" = "amd64" ]; then \
-        ARCH='amd64'; \
-    elif [ "${TARGETARCH}" = "arm64" ]; then \
-        ARCH='aarch64'; \
-    else \
-        echo "Unsupported arch: ${TARGETARCH}"; exit 1; \
-    fi && \
-    curl https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.3.1-linux-x86-64.tar.gz --output libwebp.tar.gz \
-    && tar vzxf libwebp.tar.gz \
-    && mv libwebp-1.3.1-linux-x86-64/bin/cwebp /go/bin/
-
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=$TARGETARCH go build -ldflags "-s -w -X main.version=${OYAKI_VERSION}" -o /go/bin/oyaki
+RUN CGO_ENABLED=0 go build -ldflags "-s -w -X main.version=${OYAKI_VERSION}" -o /go/bin/oyaki
+RUN apt update && apt install -y curl \
+ && curl https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.3.1-linux-x86-64.tar.gz --output libwebp.tar.gz \
+ && tar vzxf libwebp.tar.gz \
+ && mv libwebp-1.3.1-linux-x86-64/bin/cwebp /go/bin/
 
 FROM gcr.io/distroless/static-debian11