[Bug]: Ensure Tests Compile when `stylus-sdk/stylus-test` Feature is Enabled

[0xNeshi]

What happened?

When this feature is enabled on stylus-sdk, the tests cannot be built due to:

error[E0423]: expected function, tuple struct or tuple variant, found struct VM
   --> /Users/ayushboss/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/openzeppelin-stylus-0.3.0-rc.1/src/utils/storage_slot.rs:67:20
    |
67  |         let host = VM(stylus_sdk::host::WasmVM {});
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
   ::: /Users/ayushboss/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/stylus-sdk-0.9.0/src/host/mod.rs:329:9
    |
329 |         pub struct VM {
    |         ------------- VM defined here
    |
help: use struct literal syntax instead of calling
    |
67  -         let host = VM(stylus_sdk::host::WasmVM {});
67  +         let host = VM{host: stylus_sdk::host::WasmVM {}};
    |

For more information about this error, try rustc --explain E0423.
error: could not compile openzeppelin-stylus (lib) due to 1 previous error

Possibly related #730

platform

• linux
• windows
• macos

Expected behavior

Unit tests should build with the stylus-sdk/stylus-test feature enabled.

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