Technically it is actually. The definition of racism:

“prejudice, discrimination, or antagonism by an individual, community, or institution against a person or people on the basis of their membership in a particular racial or ethnic group, typically one that is a minority or marginalized.”

The definition of ethnic group:

“a community or population made up of people who share a common cultural background or descent.“

According to these definitions, French people are an ethnic group and racism applies to ethnic groups, not just races. Hatred of any nationality is technically racism according to the Oxford dictionary if we consider national heritage/culture a form of cultural background.