chore(dev): fix protoc installation script for macOS arm64 (#22221)

chore: fix protoc installation script for macOS arm64

Bump the protoc version from 3.19.5 to 3.20.2 in
`scripts/environment/install-protoc.sh`. The [3.19.5 release](https://github.com/protocolbuffers/protobuf/releases/tag/v3.19.5)
of protocol buffers don't include assets for macOS arm64, hence
the script fails on the same.
The bump is to 3.20.2 instead of 3.20.3 because for some reason, only
the [3.20.2 release](https://github.com/protocolbuffers/protobuf/releases/tag/v3.20.2)
contains assets for macOS arm64.

Furthermore, modify the flags passed to the `mv` command to be macOS
compatible.

Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>