chore: cleanup gapicgen a bit (#7703)

- remove generating module feature, only do this with owlbot now
- remove all confings no longer being generated
- remove generation of manifest, owlbot does this now

internal/gapicgen/cmd/genbot/local.go

@@ -38,7 +38,6 @@ type localConfig struct {
 	onlyGapics      bool
 	regenOnly       bool
 	forceAll        bool
-	genModule       bool
 	genAlias        bool
 }
 
@@ -75,7 +74,6 @@ func genLocal(ctx context.Context, c localConfig) error {
 		LocalMode:         true,
 		RegenOnly:         c.regenOnly,
 		ForceAll:          c.forceAll,
-		GenModule:         c.genModule,
 		GenAlias:          c.genAlias,
 	}
 	if _, err := generator.Generate(ctx, conf); err != nil {

internal/gapicgen/cmd/genbot/main.go

@@ -54,7 +54,6 @@ func main() {
 	gapicToGenerate := flag.String("gapic", os.Getenv("GAPIC_TO_GENERATE"), `Specifies which gapic to generate. The value should be in the form of an import path (Ex: cloud.google.com/go/pubsub/apiv1). The default "" generates all gapics.`)
 	onlyGapics := flag.Bool("only-gapics", strToBool(os.Getenv("ONLY_GAPICS")), "Enabling stops regenerating genproto.")
 	regenOnly := flag.Bool("regen-only", strToBool(os.Getenv("REGEN_ONLY")), "Enabling means no vetting, manifest updates, or compilation.")
-	genModule := flag.Bool("generate-module", strToBool(os.Getenv("GENERATE_MODULE")), "Enabling means a new module will be generated for API being generated.")
 	genAlias := flag.Bool("generate-alias", strToBool(os.Getenv("GENERATE_ALIAS")), "Enabling means alias files will be generated.")
 
 	flag.Parse()
@@ -69,7 +68,6 @@ func main() {
 			onlyGapics:      *onlyGapics,
 			regenOnly:       *regenOnly,
 			forceAll:        *forceAll,
-			genModule:       *genModule,
 			genAlias:        *genAlias,
 		}); err != nil {
 			log.Fatal(err)