Bump MSRV in test.yml to 1.53.0

currently, test.yml has rust 1.46.0. But...

wasmtime 0.29 (and a few of its deps) require cargo's "resolver=2",
which raises our Minimum Supported Rust Version of 1.51.0.

At least one other dep (posish) needs 1.53.0, so that bumps our MSRV
again.

Signed-off-by: Will Woods <[email protected]>

Author: wgwoods

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
           - nightly
           - beta
           - stable
-          - 1.46.0
+          - 1.53.0
         profile:
           - name: debug
           - name: release