update log streaming destination test

[leahrob]

updating the test endpoint in the hcp log streaming destination tests to pass tls validation

🛠️ Description

🏗️ Acceptance tests

• Are there any feature flags that are required to use this functionality?
• Have you added an acceptance test for the functionality being added?
• Have you run the acceptance tests on this branch?

Output from acceptance testing:

TestAccHCPLogStreamingDestinationSplunk

$ make testacc TESTARGS='-run=TestAccHCPLogStreamingDestinationSplunk'

==> Checking that code complies with gofmt requirements...
golangci-lint run --config ./golangci-config.yml 
TF_ACC=1 go test ./internal/... -v -run=TestAccHCPLogStreamingDestinationSplunk -timeout 360m -parallel=10
?       github.com/hashicorp/terraform-provider-hcp/internal/clients/iampolicy  [no test files]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/clients    (cached) [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/consul     (cached) [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/hcpvalidator       (cached) [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/input      (cached) [no tests to run]
?       github.com/hashicorp/terraform-provider-hcp/internal/provider   [no test files]
?       github.com/hashicorp/terraform-provider-hcp/internal/provider/acctest   [no test files]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/provider/iam       (cached) [no tests to run]
=== RUN   TestAccHCPLogStreamingDestinationSplunk
--- PASS: TestAccHCPLogStreamingDestinationSplunk (5.79s)
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/provider/logstreaming      6.292s
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/provider/resourcemanager   (cached) [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/provider/vaultsecrets      (cached) [no tests to run]
testing: warning: no tests to run
PASS
ok      github.com/hashicorp/terraform-provider-hcp/internal/providersdkv2      (cached) [no tests to run]
...