Update abstract-app requirement from 0.20 to 0.21

Updates the requirements on abstract-app to permit the latest version.

---
updated-dependencies:
- dependency-name: abstract-app
  dependency-type: direct:production
...

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

Cargo.toml

@@ -46,15 +46,15 @@ cw-storage-plus = "1.1.0"
 thiserror = { version = "1.0.50" }
 schemars = "0.8"
 cw-asset = { version = "3.0.0" }
-abstract-app = { version = "0.20" }
+abstract-app = { version = "0.21" }
 
 # Dependencies for interface
 cw-orch = { version = "0.19.1", optional = true }
 
 [dev-dependencies]
 app = { path = ".", features = ["interface"] }
 abstract-client = { version = "0.20" }
-abstract-app = { version = "0.20", features = ["test-utils"] }
+abstract-app = { version = "0.21", features = ["test-utils"] }
 speculoos = "0.11.0"
 semver = "1.0"
 dotenv = "0.15.0"