chore(pre-release): AS-701 test pre-release charts

[afoley587]

Rationale

In a prior PR, we had pinned helm versions in our pre-release flow to 3.17.3 because there was an issue with OCI/HTTPS repos. This appears to be fixed in 3.18.1. This PR will serve as additional testing to ensure that everything works as expected.

Changes

Removes the 3.17.3 pin on helm in the pre-release-internal-env workflow.

Checklist

• This PR maintains parity between Docker Compose and Helm

Testing

### OLD

% helm version
version.BuildInfo{Version:"v3.18.0", GitCommit:"cc58e3f5a3aa615c6a86275e6f4444b5fdd3cc4e", GitTreeState:"clean", GoVersion:"go1.24.3"}
% gcloud auth print-access-token | helm registry login -u oauth2accesstoken --password-stdin "https://us-central1-docker.pkg.dev"
Error: invalid reference: invalid registry "https://us-central1-docker.pkg.dev"
alexanderfoley@Alexanders-MacBook-Pro fiftyone-teams-app-deploy % 

### NEW

% helm version
version.BuildInfo{Version:"v3.18.1", GitCommit:"f6f8700a539c18101509434f3b59e6a21402a1b2", GitTreeState:"clean", GoVersion:"go1.24.3"}
% gcloud auth print-access-token | helm registry login -u oauth2accesstoken --password-stdin "https://us-central1-docker.pkg.dev"
Login Succeeded

[findtopher]

Let's do this thing!

[findtopher]

I dunno, without the dummy change I feel like it's really risky....

LEEERRROOOYYYY JEEEENKIIIINSSSS