feat(osv-linter): add stubs for all current defined ecosystems (#315)

Adds Red Hat and SUSE/openSUSE and sorts consistent with case
insensitive sort of OSV.dev's `ecosystems.txt`

Signed-off-by: Andrew Pollock <apollock@google.com>

tools/osv-linter/internal/pkgchecker/ecosystems.go

@@ -27,10 +27,10 @@ var SupportedEcosystems = []string{
 // Dispatcher for ecosystem-specific package existence checking.
 func ExistsInEcosystem(pkg string, ecosystem string) bool {
 	switch ecosystem {
-	case "Alpine":
-		return true
 	case "AlmaLinux":
 		return true
+	case "Alpine":
+		return true
 	case "Android":
 		return true
 	case "Bitnami":
@@ -63,6 +63,8 @@ func ExistsInEcosystem(pkg string, ecosystem string) bool {
 		return true
 	case "NuGet":
 		return true
+	case "openSUSE":
+		return true
 	case "OSS-Fuzz":
 		return true
 	case "Packagist":
@@ -71,10 +73,14 @@ func ExistsInEcosystem(pkg string, ecosystem string) bool {
 		return true
 	case "PyPI":
 		return existsInPyPI(pkg)
+	case "Red Hat":
+		return true
 	case "Rocky Linux":
 		return true
 	case "RubyGems":
 		return true
+	case "SUSE":
+		return true
 	case "SwiftURL":
 		return true
 	case "Ubuntu":
@@ -102,10 +108,10 @@ func (e *MissingVersionsError) Error() string {
 // Dispatcher for ecosystem-specific package version existence checking.
 func VersionsExistInEcosystem(pkg string, versions []string, ecosystem string) error {
 	switch ecosystem {
-	case "Alpine":
-		return nil
 	case "AlmaLinux":
 		return nil
+	case "Alpine":
+		return nil
 	case "Android":
 		return nil
 	case "Bitnami":
@@ -138,6 +144,8 @@ func VersionsExistInEcosystem(pkg string, versions []string, ecosystem string) e
 		return nil
 	case "NuGet":
 		return nil
+	case "openSUSE":
+		return nil
 	case "OSS-Fuzz":
 		return nil
 	case "Packagist":
@@ -146,10 +154,14 @@ func VersionsExistInEcosystem(pkg string, versions []string, ecosystem string) e
 		return nil
 	case "PyPI":
 		return versionsExistInPyPI(pkg, versions)
+	case "Red Hat":
+		return nil
 	case "Rocky Linux":
 		return nil
 	case "RubyGems":
 		return nil
+	case "SUSE":
+		return nil
 	case "SwiftURL":
 		return nil
 	case "Ubuntu":