fix: match the mongodb hostname

[erikmartino]

Motivation:

Rendering the template helm template sc sorry-cypress/sorry-cypress The mongo database name sc-mongodb-0 doesn't match the mongodb://sc-sorry-cypress-mongodb-0:27017 url

Modifications:

Use the .Release.Name instead of the full name in the mongodb.hostname template in _helpers.tpl

Results:

The mongodb hostname matches across the chart

Checklist:

• [] I have increased the chart version.
• [] I have updated the chart readme.
• [] I have updated the chart changelog.
• [] I have written CI tests for my change.