[Bloganuary] Replace hyphen with em dash in Bloganuary Nudge text

[thomashorta]

Use the appropriate character in the Bloganuary text for US English, it should be an em and not a hyphen. This should target a hotfix branch for the 23.8 release, likely release/23.8.1.

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To Test:

Check that the Bloganuary card on My Site dashboard shows the correct character for US English.

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Regression Notes

1. Potential unintended areas of impact

   • None

2. What I did to test those areas of impact (or what existing automated tests I relied on)

   • None

3. What automated tests I added (or what prevented me from doing so)

   • None

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PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

	Warnings
⚠️	PR is not assigned to a milestone.

Generated by 🚫 dangerJS

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr19774-4c2c9f0
	Commit	4c2c9f0
	Direct Download	wordpress-prototype-build-pr19774-4c2c9f0.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr19774-4c2c9f0
	Commit	4c2c9f0
	Direct Download	jetpack-prototype-build-pr19774-4c2c9f0.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

	1 Warning
⚠️	PR is not assigned to a milestone.

Generated by 🚫 Danger

[RenanLukas]

LGTM