README: remove install docs from packagers

They do not work for rig, temporarily.
They will be re-added soon, sonce they work again.

[ci skip]

README.Rmd

@@ -60,26 +60,6 @@ Found another issue? Please report it in our
 Download the latest release from https://github.com/r-lib/rig/releases
 and install it the usual way.
 
-### macOS (Homebrew)
-
-If you use Homebrew (Intel or Arm version), you can install rig from our
-tap:
-
-```sh
-brew tap r-lib/rig
-brew install --cask rig
-```
-
-You can use x86_64 rig on Arm macs, and it will be able to install Arm
-builds of R. But you cannot use Arm rig on Intel macs. If you use both brew
-versions, only install rig with one of them.
-
-To update rig you can run
-
-```sh
-brew upgrade --cask rig
-```
-
 ### Windows (installer)
 
 Download the latest release from https://github.com/r-lib/rig/releases
@@ -88,38 +68,6 @@ and install it the usual way.
 `rig` adds itself to the user's path, but you might need to restart your
 terminal after the installation on Windows.
 
-### Windows (Chocolatey)
-
-If you use [Chocolatey](https://chocolatey.org/) (e.g. on GitHub Actions)
-you can install `rig` with
-
-``` powershell
-choco install rig
-```
-
-and upgrade to the latest version with
-
-``` powershell
-choco upgrade rig
-```
-
-### Windows (Scoop)
-
-If you use [Scoop](https://scoop.sh/), you can install rig from the scoop
-bucket at
-[`cderv/r-bucket`](https://github.com/cderv/r-bucket#r-installation-manager-rig):
-
-``` powershell
-scoop bucket add r-bucket https://github.com/cderv/r-bucket.git
-scoop install rig
-```
-
-To update run
-
-``` powershell
-scoop update rig
-```
-
 ### Linux
 
 Download the latest releast from https://github.com/r-lib/rig/releases