tap: remove check for support GetBlockHeader

With the `minimalCompatibleVersion` bumped to `0.18.4` we can assume
support for the `GetBlockHeader` RPC call. This removes the check for
support of the `GetBlockHeader` RPC call.

Author: gijswijs

chain_bridge.go

@@ -18,7 +18,6 @@ import (
 	"github.com/lightninglabs/taproot-assets/tapgarden"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/funding"
-	"github.com/lightningnetwork/lnd/lnrpc/verrpc"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing/route"
@@ -37,8 +36,6 @@ const (
 type LndRpcChainBridge struct {
 	lnd *lndclient.LndServices
 
-	getBlockHeaderSupported *bool
-
 	blockTimestampCache *lru.Cache[uint32, cacheableTimestamp]
 
 	assetStore *tapdb.AssetStore
@@ -138,31 +135,6 @@ func (l *LndRpcChainBridge) GetBlockHash(ctx context.Context,
 	return blockHash, nil
 }
 
-// GetBlockHeaderSupported returns true if the chain backend supports the
-// `GetBlockHeader` RPC call.
-func (l *LndRpcChainBridge) GetBlockHeaderSupported(ctx context.Context) bool {
-	// Check if we've already asserted the compatibility of the chain
-	// backend.
-	if l.getBlockHeaderSupported != nil {
-		return *l.getBlockHeaderSupported
-	}
-
-	// The ChainKit.GetBlockHeader() RPC call was added in lnd v0.17.1.
-	getBlockHeaderMinimalVersion := &verrpc.Version{
-		AppMajor: 0,
-		AppMinor: 17,
-		AppPatch: 1,
-	}
-
-	getBlockHeaderUnsupported := lndclient.AssertVersionCompatible(
-		l.lnd.Version, getBlockHeaderMinimalVersion,
-	)
-	getBlockHeaderSupported := getBlockHeaderUnsupported == nil
-
-	l.getBlockHeaderSupported = &getBlockHeaderSupported
-	return *l.getBlockHeaderSupported
-}
-
 // VerifyBlock returns an error if a block (with given header and height) is not
 // present on-chain. It also checks to ensure that block height corresponds to
 // the given block header.
@@ -194,12 +166,7 @@ func (l *LndRpcChainBridge) VerifyBlock(ctx context.Context,
 	// Ensure that the block header corresponds to a block on-chain. Fetch
 	// only the corresponding block header and not the entire block if
 	// supported.
-	if l.GetBlockHeaderSupported(ctx) {
-		_, err = l.GetBlockHeader(ctx, header.BlockHash())
-		return err
-	}
-
-	_, err = l.GetBlock(ctx, header.BlockHash())
+	_, err = l.GetBlockHeader(ctx, header.BlockHash())
 	return err
 }
 
@@ -233,20 +200,10 @@ func (l *LndRpcChainBridge) GetBlockTimestamp(ctx context.Context,
 		return 0
 	}
 
-	// Let's see if we can get the block header directly.
-	var header *wire.BlockHeader
-	if l.GetBlockHeaderSupported(ctx) {
-		header, err = l.GetBlockHeader(ctx, hash)
-		if err != nil {
-			return 0
-		}
-	} else {
-		block, err := l.lnd.ChainKit.GetBlock(ctx, hash)
-		if err != nil {
-			return 0
-		}
-
-		header = &block.Header
+	// Get block header.
+	header, err := l.GetBlockHeader(ctx, hash)
+	if err != nil {
+		return 0
 	}
 
 	ts := uint32(header.Timestamp.Unix())