hcl2.Builder() quotes provider map keys, causing deprecation warnings

[shanukk27]

Summary:

When using hcl2.Builder() to generate HCL files, the providers map for module blocks includes quoted keys
e.g.,

  providers = {
    aws.route53 = "aws.route53"
    aws.rds     = "aws.rds"
  }

This triggers the following deprecation warning from Terraform (version 1.11.4):

Warning: Quoted references are deprecated

What we expect hcl2.Builder() to generate:

  providers = {
    aws.route53 = aws.route53
    aws.rds     = aws.rds
  }

Proposed Action:

Add special handling within hcl2.Builder() for providers maps:

• Do not quote the keys (provider names).
• Maintain quotes for values that actually need it (eg. strings).
• Compatibility across recent versions of Terraform.

[shanukk27]

Passing the dictionary like this works though:
providers = {"aws.route53": "${aws.route53}", "aws.s3": "${aws.s3}"}