[ML-DSA] Measure stack frame size on CI

[jschneider-bensch]

This PR contains a script for obtaining stack frame measurements in ML-DSA and checking they don't exceed a given limit.
It also introduces a new job on the ML-DSA CI for running the script and

From the script docs:
This script runs cargo stack-sizes to obtain stack frame sizes for
functions in the crate. It

• temporarily installs the cargo stack-sizes tool,
• temporarily reconfigure the crate to the requirements of cargo
  stack-sizes (installs a minimal Rust nightly toolchain and sets a
  bogus version in Cargo.toml),
• runs the stack-sizes tool on a given example.

The script will then print all stack frame sizes it collects in
increasing order and will exit normally if the FRAME_SIZE_LIMIT is
not exceeded by any of them. If the limit is exceeded the script
will error and print the name of the offending function.

Before exiting, the script will restore the previous state of the
crate and uninstall the stack-sizes tool.

Usage:

    ./stack-sizes.sh <example>

where <example> is an example program as you would run it with cargo run --example <example>.

[jschneider-bensch]

After some testing and discussion, the tool might not be as precise as we hoped. (Some discussion on this.)
Closing this in favor of a different approach for now.