Update AWS provider version to 6.30.0 in squid-proxy module

[Copilot]

Bumps the AWS provider version in the squid-proxy module from ~> 5.0 to 6.30.0, aligning with the version requirement established in the envoy-proxy module.

Changes

• modules/composition/squid-proxy/versions.tf — Updated required_providers constraint from >= 5.0 → >= 6.30.0
• live/dev/eu-central-1/squid-proxy/versions.tf — Updated live layer constraint from ~> 5.0 → ~> 6.30 (allows 6.30+ minor versions within major version 6, consistent with module constraint)
• live/dev/eu-central-1/squid-proxy/.terraform.lock.hcl — Locked to 6.30.0 with multi-platform hashes (linux/amd64, linux/arm64, darwin/amd64, darwin/arm64, windows/amd64) generated via terraform providers lock
• modules/composition/squid-proxy/README.md — Updated auto-generated provider version table

# Before
required_providers {
  aws = {
    source  = "hashicorp/aws"
    version = ">= 5.0"
  }
}

# After
required_providers {
  aws = {
    source  = "hashicorp/aws"
    version = ">= 6.30.0"
  }
}