set CROSS_SYSROOT=/ to fix cross-rs openssl issue

Signed-off-by: Rajat Jindal <[email protected]>

cross/Dockerfile

@@ -1,5 +1,10 @@
 FROM ghcr.io/cross-rs/aarch64-unknown-linux-musl@sha256:7ad32efcae37c178fed63da301ff982d2430f15fc7d39e6c0b28124e14fac394
 
+## as per analysis done in https://github.com/fermyon/spin/pull/2287#issuecomment-1970145410 we need
+## to disable the cmake config in cross-rs. Setting CROSS_SYSROOT=/ seems to have done the trick
+
+ENV CROSS_SYSROOT=/
+
 RUN --mount=type=bind,source=/,target=/polyfill /polyfill/polyfill.sh