fix(riscv): building using Rust 1.73 to avoid segmentation fault in release mode

[reubenmiller]

Proposed changes

Build riscv64gc-unknown-linux-gnu target using minimum Rust 1.73, otherwise the produced binary crashes with a "segmentation fault".

Rust 1.73 upgraded the internal use of llvm to version 17 (which includes some other improvements) which

• PR Upgrade to llvm 17 is mentioned in the Rust 1.73 release notes

Rust versions 1.70 through to 1.76 were tested on a Star Vision2 device (with a riscv processor) - where "Segmentation fault" is observed whilst initialising the c8y-remote-access-plugin (though it is not limited to this command):

user@starfive:~$ uname -a
Linux starfive 5.15.0-starfive #1 SMP Fri Nov 24 07:22:28 UTC 2023 riscv64 GNU/Linux
user@starfive:~$ sudo -u tedge ./tedge-1.70 c8y-remote-access-plugin --init
Segmentation fault
user@starfive:~$ sudo -u tedge ./tedge-1.71 c8y-remote-access-plugin --init
Segmentation fault
user@starfive:~$ sudo -u tedge ./tedge-1.72 c8y-remote-access-plugin --init
Segmentation fault
user@starfive:~$ sudo -u tedge ./tedge-1.73 c8y-remote-access-plugin --init
user@starfive:~$ sudo -u tedge ./tedge-1.74 c8y-remote-access-plugin --init
user@starfive:~$ sudo -u tedge ./tedge-1.75 c8y-remote-access-plugin --init
user@starfive:~$ sudo -u tedge ./tedge-1.76 c8y-remote-access-plugin --init
user@starfive:~$ sudo -u tedge ./tedge-1.7 c8y-remote-access-plugin --init

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.1%. Comparing base (f756b91) to head (44abd79).
Report is 37 commits behind head on main.

Additional details and impacted files

see 54 files with indirect coverage changes

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
389	0	3	389	100	0s

[didier-wenzek]

Approved