Fix "Failed to install arduino-cli" when invoked by install.sh

[brentru]

Due to PR #2374, install.sh fails to run on the latest release tag:

curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh
Installing in [dir]
ARCH=64bit
OS=macOS
Using curl as download tool
Failed to install arduino-cli

In turn, this causes repositories that have automated tooling and rely upon install.sh (such as adafruit/ci-arduino) to fail.

This pull request implements a fix suggested by @tobozo in #2370 because the v? prefix requires escaping to be passed to grep.

cc @cmaglie @per1234

[CLAassistant]

All committers have signed the CLA.

[alessio-perugini]

thank you

[jhunji1701]

Hi

It seems like this issue has been fixed, but I have a new raspberry pi that I setup today, and I am running into the same issue.

cd /usr/local && sudo curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sudo sh
Installing in /usr/local/bin
ARCH=ARMv7
OS=Linux
Using curl as download tool
Downloading https://downloads.arduino.cc/arduino-cli/arduino-cli_0.34.2_Linux_ARMv7.tar.gz
Failed to install arduino-cli

any advice would be much appreciated