[Snyk] Fix for 5 vulnerabilities

[jbowes]

This PR was automatically created by Snyk using the credentials of a real user.


Snyk has created this PR to fix 5 vulnerabilities in the npm dependencies of this project.

Snyk changed the following file(s):

• slides/plugin/multiplex/package.json

Vulnerabilities that will be fixed with an upgrade:

	Issue	Score
	Prototype Pollution SNYK-JS-LODASH-6139239	696
	Denial of Service (DoS) SNYK-JS-SOCKETIOPARSER-1056752	696
	Improper Input Validation SNYK-JS-SOCKETIOPARSER-3091012	614
	Regular Expression Denial of Service (ReDoS) npm:parsejson:20170908	589
	Open Redirect SNYK-JS-EXPRESS-6474509	519

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[!IMPORTANT]

• Check the changes in this PR to ensure they won't cause issues with your project.
• Max score is 1000. Note that the real score may have changed since the PR was raised.
• This PR was automatically created by Snyk using the credentials of a real user.

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🦉 Open Redirect 🦉 Prototype Pollution 🦉 Denial of Service (DoS) 🦉 More lessons are available in Snyk Learn