Set session cookie secure flag based on NODE_ENV

[Nishthajain7]

Issue:

Fixes #3909

Problem

The session cookie was currently configured with secure: false

Changes:

Update the session configuration to conditionally enable the secure flag when running in production.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• has no typecheck errors (npm run typecheck)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
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