Fix publication variable help translation

[Montekkundan]

Brief summary of changes

• Updates the French publication helpFindingVariables translation.
• Removes the fuzzy placeholder text so the variable help line renders as readable French.

Testing instructions (if applicable)

• Run make publication.
• Open the Publication upload form in French.
• Confirm the variable help text appears as readable French text with the Data Dictionary link.

Link(s) to related issue(s)

• Resolves [publications] Missing translated variable #10274

[skarya22]

LGTM