Terraform templatefile runtime: out of memory

Question

Im deploying my infrastructure on AWS using terraform and Ive been having this problem :

When I try to deploy my APIGW :

module my_api_gateway {
  ...
  body = templatefile(./api.tpl, local.apigw_vars)
  ...
}

I have this error :

runtime: out of memory: cannot allocate 650117120-byte block (309133312 in use)
fatal error: out of memory

goroutine 38 [running]:
runtime.throw({0x30794b5, 0xd})
        /opt/hostedtoolcache/go/1.19.6/x64/src/runtime/panic.go:1047 +0x4d fp=0x18a82e6c sp=0x18a82e58 pc=0xf289cd

I think it's due to my api.tpl file which is too large (529 Ko) ? I tried splitting the file into different sections and using a join to join different templatefiles but I still get the same error.

Any ideas how I can fix this ?

Edit : Here are the local variables :

body = templatefile(local.swagger_file, {
    name                                        = "api-gateway-private-api-${var.id}",
    description                                 = "API Gateway for ${var.application_name} API",
    version                                     = "1.0.0",
    contact_name                                = var.api_contact_name,
    contact_email                               = var.api_contact_email,
    nlb_dns_name                                = aws_lb.this.dns_name,
    swagger_sha                                 = sha256(local.swagger_file),
    api_gateway_vpc_link_id                     = aws_api_gateway_vpc_link.this.id,
    env                                         = local.dns_env,
    project                                     = var.project,
    policy                                      = data.aws_iam_policy_document.access_policy.json,
    vpc_endpoint                                = var.vpc_endpoint_apigateway_id,
    api_uri                                     = "${var.api_protocol}://${var.api_uri}",
    api_header_aca_origin                       = var.api_header_aca_origin,
    api_header_sts                              = var.api_header_sts
    lambda_1                                    = "arn:aws:lambda:eu-west-3:${data.aws_caller_identity.current.account_id}:function:${local.lambda1.name}"
    lambda_2                                    = "arn:aws:lambda:eu-west-3:${data.aws_caller_identity.current.account_id}:function:lambda2"
    sqs_1                                       = "${data.aws_caller_identity.current.account_id}/${var.project}-${var.env}-sqs-1"
  })