chore(deps): update rust crate tauri-plugin-theme to v2

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
tauri-plugin-theme	dependencies	major	0.2.0 -> 2.0.0

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[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
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The artifact failure details are included below:

File name: src-tauri/Cargo.lock

Command failed: cargo update --config net.git-fetch-with-cli=true --manifest-path src-tauri/Cargo.toml --workspace
    Updating crates.io index
error: failed to select a version for `webkit2gtk-sys`.
    ... required by package `webkit2gtk v0.18.2`
    ... which satisfies dependency `webkit2gtk = "^0.18.2"` of package `tauri v1.5.0`
    ... which satisfies dependency `tauri = "^1.5"` of package `translator-cheatsheet v0.0.0 (/tmp/renovate/repos/github/ba-archive/translator-cheatsheet/src-tauri)`
versions that meet the requirements `^0.18` are: 0.18.0

the package `webkit2gtk-sys` links to the native library `web_kit2`, but it conflicts with a previous package which links to `web_kit2` as well:
package `webkit2gtk-sys v2.0.1`
    ... which satisfies dependency `ffi = "^2.0.1"` of package `webkit2gtk v2.0.1`
    ... which satisfies dependency `webkit2gtk = "=2.0.1"` of package `tauri v2.0.0-rc.0`
    ... which satisfies dependency `tauri = "^2.0.0-rc"` of package `tauri-plugin-theme v2.0.0`
    ... which satisfies dependency `tauri-plugin-theme = "^2.0.0"` of package `translator-cheatsheet v0.0.0 (/tmp/renovate/repos/github/ba-archive/translator-cheatsheet/src-tauri)`
Only one package in the dependency graph may specify the same links value. This helps ensure that only one copy of a native library is linked in the final binary. Try to adjust your dependencies so that only one package uses the `links = "web_kit2"` value. For more information, see https://doc.rust-lang.org/cargo/reference/resolver.html#links.

failed to select a version for `webkit2gtk-sys` which could resolve this conflict