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]

assets/text/Monerocom_Release_Notes.txt

@@ -1,3 +1,3 @@
-Monero enhancements
-Introducing StealthEx and LetxExchange
+Add airgapped Monero wallet support (best used with our new offline app Cupcake)
+New Buy & Sell flow
 Bug fixes

assets/text/Release_Notes.txt

@@ -1,7 +1,5 @@
-Added Litecoin MWEB
-Added wallet groups
-Silent Payment enhancements for speed & reliability
-Monero enhancements
-Introducing StealthEx and LetxExchange
-Additional ERC20 tokens scam detection
+Add Litecoin Ledger support
+Add airgapped Monero wallet support (best used with our new offline app Cupcake)
+MWEB fixes and enhancements
+New Buy & Sell flow
 Bug fixes