Rust: add binary blobs

[florianl]

This is a complementary change to #408.
It adds the Rust binary blobs to git and adds a CI check to verify their integrity.

Unfortunately, the Dockerfile needs to be updated to allow this cross compilation for Rust. The CI will fail in the scope of check-rust-blobs as the updated docker image will only be available once the changes to the Dockerfile got merged into main.

[rockdaboot]

Is this required (maybe i don't understand the exact purpose here)? Once you git add -f the *.a files, git status they are excluded from target/ (yes, /target should indeed be target/.

[christos68k]

Right, these shouldn't be needed. Our current .gitignore works.

[christos68k]

This can be simplified and sped up, as we don't need the extra step to hash and verify the hashes. We can also let the user know exactly which blob(s) actually changed, instead of printing a generic message:

Suggested change

	- name: Hash Rust blobs
	run: |
	sha256sum target/*-unknown-linux-musl/release/libsymblib_capi.a > rust-blobs.hash
	- name: Rebuild Rust blobs
	run: |
	rm -rf target/
	make rust-components TARGET_ARCH=amd64
	make rust-components TARGET_ARCH=arm64
	- name: Check for differences
	run: |
	if ! sha256sum --check rust-blobs.hash; then
	echo "Please rebuild and commit the updated Rust binary blobs."
	exit 1
	fi
	- name: Rebuild Rust blobs
	run: |
	rm -rf target/
	make rust-components TARGET_ARCH=amd64
	make rust-components TARGET_ARCH=arm64
	- name: Check for differences
	run: |
	if ! git diff --exit-code --name-only; then
	echo "Binary blob(s) changed, please rebuild and commit the updated blobs."
	exit 1
	fi

We should do the same for the tracers.