fix(route53): correct traffic policy behavior (#27767)

[Dhruvin1]

Description

This PR enhances the aws_route53_traffic_policy resource to properly support versioning when updating traffic policy documents. Previously, updates to the traffic policy document would overwrite existing versions rather than creating a new version as expected. This change ensures that when a traffic policy document is modified, a new version is created while preserving previous versions, aligning with AWS Route53 API behavior and user expectations.

Relations

Closes #27767

References

• AWS Route53 API documentation on CreateTrafficPolicyVersion
• AWS Route53 behavior maintains historical versions of traffic policies which this PR now correctly models

Output from Acceptance Testing

% make testacc TESTS=TestAccRoute53TrafficPolicy_updateDocument PKG=route53
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./internal/service/route53/... -v -count 1 -parallel 20 -run=TestAccRoute53TrafficPolicy_updateDocument -timeout 360m
2025/04/24 15:28:42 Initializing Terraform AWS Provider...
=== RUN   TestAccRoute53TrafficPolicy_updateDocument
=== PAUSE TestAccRoute53TrafficPolicy_updateDocument
=== CONT  TestAccRoute53TrafficPolicy_updateDocument
--- PASS: TestAccRoute53TrafficPolicy_updateDocument (19.19s)
PASS
ok  	github.com/hashicorp/terraform-provider-aws/internal/service/route53	23.751s


### Credits
Credit to @IamEnTm for the original fork and implementation of the versioned update approach.
This PR is being submitted on behalf of Palo Alto Networks CDSS DNS Security team, where the issue was reproduced, fixed and validated.

[github-actions]

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[github-actions]

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[Dhruvin1]

Hi, can anyone please review this merge request?