Update rust2rpm / tools and RPM macros for Rust packaging to version 23.

Added:

• New macros for collecting license information for all crates that are statically linked into a Rust binary (%cargo_license and %cargo_license_summary).
• Add support for specifying "testrequires" in rust2rpm.conf. These work similar to "buildrequires", but the specified dependencies will be wrapped in an %if %{with check} conditional in the generated spec file. This can be used to specify BuildRequires that are only needed when running a crate's test suite, but which are not necessary to build the crate itself.

Changed:

• The list of binaries in %files is now consistently sorted in generated spec files (this only affects crates that build more than one binary, of course).
• Fall back to the latest pre-release if there are no stable releases (or if all previously published stable released have been yanked).
• Dropped ExclusiveArch: %{rust_arches} when generating spec files for Fedora. RPM itself will start to depend on Rust components, so Rust will by definition need to be available on all architectures that are supported by Fedora.
• Replaced i686 with the %{ix86} macro in %{rust_arches}.

Fixed:

• Ensure that rust2rpm doesn't auto-generate architecture-dependent patches.
• Ensure both automatically generated and manually written patches affect spec file generation (i.e. feature subpackages).
• Fix evaluation of cfg-expressions that contain the new "wasm64" target.
• Only remove target-specific dependencies from feature dependencies if they are optional.
• The logic for replacing the current version of rust2rpm when comparing spec output in tests has been fixed for OpenSUSE spec templates.