chore(session): require setup function to use session command

[emilyrohrbough]

• Closes #24311

Nothing in our docs indicates that setup is optional and by allowing it to be optional diverages from the concept of each test should be able to run independently from one-another because the session had to be been creates at least once to omit the setup function without an error.

Note: This is a breaking change in the experimental API.

User facing changelog

The cy.session() command now requires a setup command to use the command. Addresses #24311.

PR Tasks

• Have tests been added/updated?
• Has the original issue (or this PR, if no issue exists) been tagged with a release in ZenHub? (user-facing changes only)
• [n/a] Has a PR for user-facing changes been opened in cypress-documentation?
• Have API changes been updated in the type definitions?

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[cypress]

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Test summary

192 • 0 • 26 • 0 • 2

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Run details

Project	cypress
Status	Passed
Commit	e7fbe0d
Started	Oct 25, 2022 2:22 PM
Ended	Oct 25, 2022 2:32 PM
Duration	09:55 💡
OS	Linux Debian - 11.4
Browser	Chrome 106

View run in Cypress Dashboard ➡️

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Flakiness

	scaffold-component-testing.cy.ts		1
1	scaffolding component testing > vuecli5vue3 > scaffolds component testing for Vue CLI 5 w/ Vue 3 project
	global-mode.cy.ts		1
1	Launchpad: Global Mode > when projects have been added > updates most-recently opened project list when returning from next step

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