cargo: bump rust edition to 2024

[muzarski]

According to documentation, the no_mangle attribute is considered unsafe and compiler emits errors when it's used without unsafe() marker.

See: https://doc.rust-lang.org/edition-guide/rust-2024/unsafe-attributes.html

Pre-review checklist

• I have split my patch into logically separate commits.
• All commit messages clearly explain what they change and why.
• PR description sums up the changes and reasons why they should be introduced.
• I have implemented Rust unit tests for the features/changes introduced.
• I have enabled appropriate tests in .github/workflows/build.yml in gtest_filter.
• I have enabled appropriate tests in .github/workflows/cassandra.yml in gtest_filter.