ci: Replace brightsign/ec2-github-runner with machulav/ec2-github-runner

Our brightsign/ec2-github-runner is too old and GitHub is refusing the
connection from old client. When updating ec2-github-runner, I've noticed
that there is now built in support for running the runner as service as
a specified user.

Instead of using our own fork, I decided to switch to using the upstream

Author: caneraltinbasak

.github/workflows/bs_electron_ci_ec2.yml

@@ -53,7 +53,7 @@ jobs:
 
       - name: Start EC2 runner
         id: start-ec2-runner
-        uses: brightsign/ec2-github-runner@0fa8b183dd4124fd191ccdbc48b68f0ea46a9634
+        uses: machulav/ec2-github-runner@v2
         with:
           mode: start
           github-app-private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
@@ -62,7 +62,8 @@ jobs:
           ec2-instance-type: ${{ inputs.instance_type }}
           subnet-id: ${{ env.VPC_SUBNET_ID }}
           security-group-id: ${{ env.VPC_SG_ID }}
-          run-as-service-with-user: ubuntu
+          run-runner-as-service: true
+          run-runner-as-user: ubuntu
           runner-home-dir: /home/ubuntu
           # iam-role-name: my-role-name # optional, requires additional permissions
           aws-resource-tags: > # optional, requires additional permissions
@@ -98,11 +99,11 @@ jobs:
           aws-region: ${{ inputs.aws_region }}
 
       - name: Stop EC2 runner
-        uses: brightsign/ec2-github-runner@0fa8b183dd4124fd191ccdbc48b68f0ea46a9634
+        uses: machulav/ec2-github-runner@v2
         with:
           mode: stop
           github-app-private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
           github-app-id: 287690
           label: ${{ needs.start-runner.outputs.label }}
           ec2-instance-id: ${{ needs.start-runner.outputs.ec2-instance-id }}
-          leave-ec2-instance-running:  ${{ inputs.leave_ec2_instance_running }}
+          leave-ec2-instance-running:  ${{ inputs.leave_ec2_instance_running }}