Install script INSTALL_K3S_PR support does not work if CI has run more than once

[brandond]

If the action runs multiple times (say due to being restarted to address a flake), the RUN_ID expression may return multiple results:

k3s/install.sh

Lines 496 to 497 in 1d22b69

	# Extract the Run ID from the build workflow and lookup artifacts associated with the run
	RUN_ID=$(echo "$build_workflow" | jq -r ' .details_url' | awk -F'/' '{print $(NF-2)}')

#8 1.395 + RUN_ID='9118227575
#8 1.395 9118227594'
#8 1.396 ++ curl -s -H 'Authorization: Bearer xxx' 'https://api.github.com/repos/k3s-io/k3s/actions/runs/9118227575
#8 1.396 9118227594/artifacts'
#8 1.402 + artifacts=

[brandond]

cc @dereknola

[brandond]

no backports, since install script changes only go to master

[ShylajaDevadiga]

Validated using PR number 10113 on master branch

Environment Details

Infrastructure
Cloud EC2 instance
Cluster Configuration:
Single node

Steps to validate

1. export GITHUB_TOKEN
2. Install install a merged commit where CI ran more than once

> curl -fL https://get.k3s.io | INSTALL_K3S_PR=10113 sh -s -
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 35365  100 35365    0     0   124k      0 --:--:-- --:--:-- --:--:--  125k
[INFO]  Using PR 10113 as release
[INFO]  Downloading hash https://api.github.com/repos/k3s-io/k3s/actions/artifacts/1511389615/zip
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100  120M  100  120M    0     0  26.2M      0  0:00:04  0:00:04 --:--:-- 28.3M
[INFO]  Verifying binary download
[INFO]  Installing k3s to /usr/local/bin/k3s
[INFO]  Skipping installation of SELinux RPM
[INFO]  Creating /usr/local/bin/kubectl symlink to k3s
[INFO]  Creating /usr/local/bin/crictl symlink to k3s
[INFO]  Creating /usr/local/bin/ctr symlink to k3s
[INFO]  Creating killall script /usr/local/bin/k3s-killall.sh
[INFO]  Creating uninstall script /usr/local/bin/k3s-uninstall.sh
[INFO]  env: Creating environment file /etc/systemd/system/k3s.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s.service
[INFO]  systemd: Enabling k3s unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s.service → /etc/systemd/system/k3s.service.
[INFO]  systemd: Starting k3s