Update indexer terraform file to match testnet and mainnet configs

[jusbar23]

Changes

• Upgrade aws/hashicorp to 5.95.0 to support valkey
• Followed the aws/hashicorp 5.0 upgrade guide - https://registry.terraform.io/providers/hashicorp/aws/latest/docs/guides/version-5-upgrade?utm_source=chatgpt.com#assume_role_with_web_identity.duration_seconds-1
• Change elasticache redis to valkey v8.0
• Create variables for indexer tasks and set variables to match values in testnet/internal mainnet
• Upgrade postgres to 17.4 (To match prod)
• Match backup_retention_period, performance_insights_retention_period, auto_minor_version_upgrade, multi_az to match testnet for aws_db_instance.main

Testing

Testnet plan output terraform plan

• https://app.terraform.io/app/dydxprotocol/workspaces/indexer-public-testnet/runs/run-1L1RCLRdh8FTS6nD

Internal mainnet plan output terraform plan

• https://app.terraform.io/app/dydxprotocol/workspaces/mainnet-internal-indexer/runs/run-9xB5PE6MfNkVs9Li

[UnbornAztecKing]

This plan will delete the testnet db read replica.