schemas: "description" field in "wait(any)invoice" is optional since BOLT12

For BOLT12 invoices, the "description" is field missing in the invoice
responses. Update the schemas accordingly:

- `doc/schemas/lightning-waitanyinvoice.json`
- `doc/schemas/lightning-waitinvoice.json`

Also commit the generated msggen, cln-grpc, cln-rpc and pyln-grpc-proto files.

Changelog-Fixed: schemas: Make description in `Wait(any)invoiceResponse` optional to handle BOLT12

Author: laanwj

cln-grpc/proto/node.proto

@@ -33516,7 +33516,6 @@
       "response": {
         "required": [
           "label",
-          "description",
           "payment_hash",
           "status",
           "created_index",
@@ -33877,7 +33876,6 @@
       "response": {
         "required": [
           "label",
-          "description",
           "payment_hash",
           "status",
           "created_index",

cln-grpc/src/convert.rs

@@ -29,7 +29,6 @@
   "response": {
     "required": [
       "label",
-      "description",
       "payment_hash",
       "status",
       "created_index",

cln-rpc/src/model.rs

@@ -30,7 +30,6 @@
   "response": {
     "required": [
       "label",
-      "description",
       "payment_hash",
       "status",
       "created_index",