ci/check-semver: Fix semver failed step

[lexnv]

The semver-check is failing with the following error:

error[E0658]: use of unstable library feature 'error_in_core'
  --> /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/frame-decode-0.5.0/src/decoding/extrinsic_decoder.rs:56:6
   |
56 | impl core::error::Error for ExtrinsicDecodeError {}
   |      ^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #103765 <https://github.com/rust-lang/rust/issues/103765> for more information
   = help: add `#![feature(error_in_core)]` to the crate attributes to enable
   = note: this compiler was built on 2024-05-31; consider upgrading it if it is out of date

This is related to the toolchain nightly version 1.80. In rust, 1.81 the core::error::Error is stable.

After updating the rust-toolchain, parity-publish crate must be updated as well.
The cargo-semver-checks dependency of parity-publish crate is updated from 0.34 to 0.38.
This update enables rustdoc v36 that fixes the following issue:

 validating prdocs...
checking file changes...
checking semver changes...
(1/18) building frame-support-HEAD...
(2/18) building frame-support-28.0.0...
Error: rustdoc format v36 for file /__w/polkadot-sdk/polkadot-sdk/target/doc/frame_support.new is not supported

This PR is pending on a release of parity-publish to version 0.9.0 (fixes already on origin/master)