In general, the simple present emphasizes the habit; the present progressive emphasizes the present moment. These sentence pairs are both equally acceptable, but can have slightly different meanings:
That team misses a lot of free throws. (simple present)
The team has a habit of missing free throws, but they may not be doing so right now. In fact, the team may not even be playing right now.
That team is missing a lot of free throws. (present progressive)
We are watching a game right now, and the team has missed many free throws.
Here is another example:
I am travelling to France every week on business.
This emphasizes that my life, right now, has a lot of business travel.
I travel to France every week on business.
I am in the habit of travelling to France. The reader might infer that it is affecting me right now, but I don't explicitly say so.
With that in mind, "Every year I am going to France for my holidays" sounds awkward because something that happens only once per year doesn't seem relevant to the present moment. So the simple present is a better choice for you.