fix: add explicit dependency on rigetti-pyo3's "time" feature (#476)

In rigetti/rigetti-pyo3#45 (and rigetti/rigetti-pyo3#46), I moved all
references to the Python time types under the "time" feature.  This
was a bugfix, but I didn't realize it was also a breaking change – any
library that relied on the time types implicitly being available would
break, just as this one did!  This adds the missing feature
dependency, and I've also upgraded rigetti/rigetti-pyo3#46 to be a
breaking change.

This commit also updates Cargo.lock to force the update to
rigetti-pyo3, meaning that builds will fail without the substantive
change.

Closes #475.

Author: antalsz

Cargo.lock

@@ -28,7 +28,7 @@ numpy = "0.20.0"
 pyo3 = { version = "0.20.0", features = ["extension-module"] }
 pyo3-asyncio = { version = "0.20", features = ["tokio-runtime"] }
 pyo3-build-config = "0.20.0"
-rigetti-pyo3 = { version = "0.3.1", default-features = false, features = ["complex"] }
+rigetti-pyo3 = { version = "0.3.1", default-features = false, features = ["time", "complex"] }
 
 # The primary intent of these options is to reduce the binary size for Python wheels
 # since PyPi has limits on how much storage a project can use.