Revert shuffling algorithm for block TXs (#5839) (#5842)

Fixes the error introduced in 1.4.5 that changes the order of the TX shuffle in blocks

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 See [RELEASE](./RELEASE.md) for workflow instructions.
 
+## Release v1.4.6
+
+### Improvements
+
+* [#5839](https://github.com/spacemeshos/go-spacemesh/pull/5839) Fix a bug where nodes would stop agreeing on the order
+  of TX within a block.
+
 ## Release v1.4.5
 
 ### Improvements

blocks/utils.go

@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"math"
 	"math/big"
-	"math/rand/v2"
+	"math/rand"
 	"sort"
 
 	"github.com/seehuhn/mt19937"

txs/conservative_state.go

@@ -2,10 +2,9 @@ package txs
 
 import (
 	"context"
-	"encoding/binary"
 	"fmt"
 	"math"
-	"math/rand/v2"
+	"math/rand"
 	"time"
 
 	"github.com/spacemeshos/go-spacemesh/common/types"
@@ -108,9 +107,7 @@ func getProposalTXs(
 		return result
 	}
 	// randomly select transactions from the predicted block.
-	var seed [32]byte
-	binary.LittleEndian.PutUint64(seed[:], uint64(time.Now().UnixNano()))
-	rng := rand.New(rand.NewChaCha8(seed))
+	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
 	return ShuffleWithNonceOrder(logger, rng, numTXs, predictedBlock, byAddrAndNonce)
 }
 

txs/utils.go

@@ -1,7 +1,7 @@
 package txs
 
 import (
-	"math/rand/v2"
+	"math/rand"
 
 	"github.com/spacemeshos/go-spacemesh/common/types"
 	"github.com/spacemeshos/go-spacemesh/log"