Drywall – Do I need to fill in the gap between the wall and the laminate flooring

I had a similar situation when I redid my basement - couldn't put baseboard in to hide the gap between the doorway and the laminate flooring at the entry door. The most common solution I've seen in images I found on the web and in my chosen home improvement store was to use color coordinated T-moulding along the doorway right up against the bottom sill. I'd add an image, but I don't have one handy, alas.

If your floors have their seams lined-up like the diagram (very wrong), it looks quite bad already so adding a bunch of scraps on the end won't hurt. The best solution is to literally start over & use as many of the old pieces in the manufacturer's instructions followed new & proper floors...that have at least 3 rows laid as a dry fit so you don't have any pieces shorter than 30cm.

Each row of planks has its butt seams offset from the next row & at least the same for a third row before you repeat. One main reason for this is exactly your situation here. Be careful & conscious with your measurements & cut 1 board at a time...do I leave the line, cut-out the line or split the line.

With varied lengths meeting the wall you can custom cut & even scribe each piece's end for a flawless fit or common very minor manufacturer's gap. Also, any ridges, popped nail heads, splintered subfloor faces, heavy paint or glue deposits, etc. should all be flattened, leveled, sanded, chiseled & removed prior to installing the new floor.