Build dynamic versions of musl, curl, openssl, zlib, libgcc & guile

This is required for the Guix bootstrap to work.

steps/gcc-10.5.0/pass1.sh

@@ -173,7 +173,6 @@ src_configure() {
     # For this GCC, we only build one stage, as extra is superfluous,
     # since we build GCC 12 straight after.
     CFLAGS="-std=gnu11" \
-    LDFLAGS="-static" \
     ../configure \
         --prefix="${PREFIX}" \
         --libdir="${LIBDIR}" \
@@ -181,7 +180,6 @@ src_configure() {
         --target="${TARGET}" \
         --host="${TARGET}" \
         --disable-bootstrap \
-        --enable-static \
         --program-transform-name= \
         --enable-languages=c,c++ \
         --with-system-zlib \