fix: "or-later" suffix updated to consider deprecated "+" operator (#1907)

* fix: or-later suffix has been updated to consider deprecated +

If a given license has the suffix "or-later" it previously could have
been considered or represented with a "+". Example "GFDL-1.0-or-later"
could have been represented as "GFDL-1.0+". This PR allows the license
list generation to consider "or-later" as == to "+" when generating
permutations for upgrading deprecated licenses.

---------

Signed-off-by: Christopher Phillips <christopher.phillips@anchore.com>

internal/spdxlicense/generate/license.go

@@ -77,11 +77,16 @@ func (l License) canReplace(deprecated License) bool {
 
 func buildLicenseIDPermutations(cleanID string) (perms []string) {
 	lv := findLicenseVersion(cleanID)
+	addPlusPermutation := strings.HasSuffix(cleanID, "orlater")
 	vp := versionPermutations(lv)
-
 	permSet := strset.New()
 	version := strings.Join(lv, ".")
 	for _, p := range vp {
+		if addPlusPermutation {
+			base := strings.TrimSuffix(cleanID, "orlater")
+			plus := p + "+"
+			permSet.Add(strings.Replace(base, version, plus, 1))
+		}
 		permSet.Add(strings.Replace(cleanID, version, p, 1))
 	}