Fix CI regression: Install glibc

Problem: CI build fails on amd64 with "./coursier: not found" (exit code
127). The coursier binary downloads successfully (22.2MB) but cannot
execute. Incorrect assumption that x86_64 coursier v2.1.24 is a static
musl build. The official coursier binary for x86_64 actually requires
glibc, not musl. Previous code only installed glibc for ARM64, causing
amd64 builds to fail.

Author: jserv

Dockerfile

@@ -54,15 +54,14 @@ ARG TARGETARCH
 
 RUN mkdir /coursier_cache
 
-# Install glibc for ARM64 coursier binary (x86-64 uses static musl build)
+# Install glibc for coursier binaries (both amd64 and arm64 require glibc)
 RUN \
-    apk add --no-cache curl && \
+    apk add --no-cache curl wget gcompat libstdc++ && \
+    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub && \
+    wget -q https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.35-r1/glibc-2.35-r1.apk && \
+    apk --no-cache --force-overwrite add glibc-2.35-r1.apk && \
+    rm glibc-2.35-r1.apk && \
     if [ "$TARGETARCH" = "arm64" ]; then \
-        apk add --no-cache wget gcompat libstdc++ && \
-        wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub && \
-        wget -q https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.35-r1/glibc-2.35-r1.apk && \
-        apk --no-cache --force-overwrite add glibc-2.35-r1.apk && \
-        rm glibc-2.35-r1.apk && \
         ln -s /lib/ld-musl-aarch64.so.1 /lib/ld-linux-aarch64.so.1 2>/dev/null || true; \
     fi