Switch back the toolchain to "stable" in the build and test CI jobs

[fvaleye]

Description

A workaround has been created by freezing the version of rust in the CI jobs to v0.16.4 to unblock the Windows CI job failure with the latest Rust versions.
When the v0.17.0 version of Rust is published, we should switch back to "stable" in the toolchain setting.

Lines:

• https://github.com/delta-io/delta-rs/pull/923/files#diff-5c3fa597431eda03ac3339ae6bf7f05e1a50d6fc7333679ec38e21b337cb6721R42
• https://github.com/delta-io/delta-rs/pull/923/files#diff-5c3fa597431eda03ac3339ae6bf7f05e1a50d6fc7333679ec38e21b337cb6721R67

Related Issue(s)

• Fix cargo clippy issues 0.1.65 in Rust #923

[roeap]

we switched back to stable as part of #1097