AO3-7517 Disable phone number detection in emails on iOS

[not-varram]

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Issue

https://otwarchive.atlassian.net/browse/AO3-7517 (Please fill in issue number and remove this comment.)

Purpose

What does this PR do?

Prevent IOS from considering numerical strings of certain lengths as phone numbers via adding a certain meta tag to the email.

Credit

varram (he/him)

[pmonfort]

Thanks for working on this! The update looks good, I left a couple of small comments

[pmonfort]

Could you also update the existing meta tag on line 2 to use a self-closing /> ? I know is not related to your change but is a good opportunity to update it to match the rest of the project's layouts

[pmonfort]

The project uses have_xpath in mailer specs for checking HTML structure. Could you use that instead of parsing with Nokogiri directly? Something like:

Suggested change

	it "disables phone number detection in the HTML version" do
	html = Nokogiri::HTML(email.html_part.decoded)
	expect(html.at_xpath("//meta[@name='format-detection'][@content='telephone=no']")).to be_present
	end
	it "disables phone number detection in the HTML version" do
	expect(email.html_part).to have_xpath("//meta[@name='format-detection'][@content='telephone=no']")
	end