docs(tvix/nar-bridge): remove redundant comments

These really only describe what the code is doing, remove.

Pointed out in
https://cl.tvl.fyi/c/depot/+/9652/comment/987b3b7f_c7b5e47b/

Change-Id: I512a274295244f96744a489871861fed9523bb37
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9654
Reviewed-by: Brian McGee <brian@bmcgee.ie>
Tested-by: BuildkiteCI

tvix/nar-bridge/pkg/http/narinfo_get.go

@@ -53,14 +53,12 @@ func renderNarinfo(
 
 	log = log.WithField("pathInfo", pathInfo)
 
-	// The PathInfo received needs to be valid, and contain a NARInfo field.
 	if _, err := pathInfo.Validate(); err != nil {
 		log.WithError(err).Error("unable to validate PathInfo")
 
 		return fmt.Errorf("unable to validate PathInfo: %w", err)
 	}
 
-	// Ensure the PathInfo contains a NARInfo field
 	if pathInfo.GetNarinfo() == nil {
 		log.Error("PathInfo doesn't contain Narinfo field")