internal/rosa: populate Anitya project ids

This enables release monitoring for all applicable projects.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/flex.go

@@ -25,5 +25,7 @@ func init() {
 		Name:        "flex",
 		Description: "scanner generator for lexing in C and C++",
 		Website:     "https://github.com/westes/flex/",
+
+		ID: 819,
 	}
 }