fix(deps): update rust crate downcast-rs to v2

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
downcast-rs	dependencies	major	1.2.1 -> 2.0.0

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Release Notes

marcianx/downcast-rs (downcast-rs)

v2.0.1

Compare Source

Change

• Updated how code conditioned on the sync flag is written in the crate
  documentation to work around a crates.io doc rendering
  bug.

v2.0.0

Compare Source

Added

• Gated the sync/Arc downcasting functionality behind a new sync feature
  that is enabled by default.
• Added a new DowncastSend trait to support downcasting to Box<Any + Send>
  and made DowncastSync extend this trait.
• Added downcasting support to Box<Any + Send + Sync> to DowncastSync.

Change

• Updated minimum supported rust version 1.56 to enforce the
  rustdoc::bare_urls lint (1.53) and switch to edition 2021 (1.56).

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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: Cargo.lock

Command failed: cargo update --config net.git-fetch-with-cli=true --manifest-path crates/froglight-block/Cargo.toml --package [email protected] --precise 2.0.1
    Updating crates.io index
error: failed to select a version for the requirement `downcast-rs = "^1.2.0"`
candidate versions found which didn't match: 2.0.1
location searched: crates.io index
required by package `bevy_app v0.15.1`
    ... which satisfies dependency `bevy_app = "^0.15"` (locked to 0.15.1) of package `froglight-block v0.1.0 (/tmp/renovate/repos/github/EightFactorial/FrogLight/crates/froglight-block)`