Update leptos requirement from 0.6.13 to 0.7.0

Updates the requirements on [leptos](https://github.com/leptos-rs/leptos) to permit the latest version.
- [Release notes](https://github.com/leptos-rs/leptos/releases)
- [Commits](leptos-rs/leptos@v0.6.13...v0.7.0)

---
updated-dependencies:
- dependency-name: leptos
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

viewr/Cargo.toml

@@ -14,7 +14,7 @@ path = "src/viewr.rs"
 [dependencies]
 data_model = { path = "../data_model" }
 console_error_panic_hook = "0.1.7"
-leptos = { version = "0.6.13", features = ["csr"] }
+leptos = { version = "0.7.0", features = ["csr"] }
 leptos_router = { version = "0.6.13", features = ["csr"] }
 reqwasm = "0.5"
 serde = { version = "1", features = ["derive"] }