v4.21.0 Release Candidate (#1795)

* new versions

* minor fix of cache key

* fix cache hit

* - potential improvement for sync status
- update with latest main

* disable thorchain by default [skip ci]

* update monero_c commit hash

* minor fixes
update versions

* remove monero ledger

* increase macos build number [skip ci]

scripts/prepare_moneroc.sh

@@ -8,7 +8,7 @@ if [[ ! -d "monero_c" ]];
 then
     git clone https://github.com/mrcyjanek/monero_c --branch master
     cd monero_c
-    git checkout 1d8e0fb30b53c28756f23676d5a3e1a99a9b3051
+    git checkout d72c15f4339791a7bbdf17e9d827b7b56ca144e4
     git reset --hard
     git submodule update --init --force --recursive
     ./apply_patches.sh monero