fix(ci): count for bootnode discovery service (#3517)

Please provide a paragraph or two giving a summary of the change,
including relevant motivation and context.

# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [ ] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [ ] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [ ] Every change is related to the PR description.
- [ ] I have
[linked](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)
this pull request to relevant issues (if any exist).

yarn-project/p2p-bootstrap/terraform/main.tf

@@ -61,7 +61,8 @@ resource "aws_cloudwatch_log_group" "aztec-bootstrap-log-group" {
 }
 
 resource "aws_service_discovery_service" "aztec-bootstrap" {
-  name = "${var.DEPLOY_TAG}-aztec-bootstrap-${count.index + 1}"
+  count = local.bootnode_count
+  name  = "${var.DEPLOY_TAG}-aztec-bootstrap-${count.index + 1}"
 
   health_check_custom_config {
     failure_threshold = 1