fix: bump datadog forwarder version

`3.100.0` uses python 3.11 (https://github.com/DataDog/datadog-serverless-functions/releases)

`3.27.0` used python 3.7, which is discontinued from use in lambdas:

`Error: waiting for CloudFormation Stack (arn:aws:cloudformation:us-east-2:591234544403:stack/sbytsko-model-inference-development-datadog-forwarder/e3702a20-cf56-11ee-b589-069aef2f5291) create: failed to create CloudFormation stack, rollback requested (ROLLBACK_COMPLETE): ["The following resource(s) failed to create: [ForwarderZipCopier]. Rollback requested by user." "Resource handler returned message: \"The runtime parameter of python3.7 is no longer supported for creating or updating AWS Lambda functions. We recommend you use the new runtime (python3.12) while creating or updating functions. (Service: Lambda, Status Code: 400, Request ID: a66f6168-4d35-4951-a6ad-34f9fb2e44f6)\" (RequestToken: f1ccfe80-2ed5-56d9-2651-c67973f02bda, HandlerErrorCode: InvalidRequest)"]`

vars.tf

@@ -66,7 +66,7 @@ variable "log_exclude_at_match" {
 variable "dd_forwarder_template_version" {
   description = "Sets Datadog Forwarder version to use"
   type        = string
-  default     = "3.27.0"
+  default     = "3.100.0"
 }
 
 variable "dd_forwarder_dd_site" {