internal/history: document Go 1.22.6 and 1.21.13 releases

Change-Id: If5481efb371aad0c61c4d0a0aec4ecbb8ebd3600
Reviewed-on: https://go-review.googlesource.com/c/website/+/603455
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/history/release.go

@@ -13,6 +13,20 @@ import "html/template"
 //
 // The table is sorted by date, breaking ties with newer versions first.
 var Releases = []*Release{
+	{
+		Date: Date{2024, 8, 6}, Version: Version{1, 22, 6},
+		Bug: &FixSummary{
+			Components: []template.HTML{"the <code>go</code> command", "the compiler", "the linker", "the <code>trace</code> command", "the <code>covdata</code> command"},
+			Packages:   []string{"bytes", "go/types", "os/exec"},
+		},
+	},
+	{
+		Date: Date{2024, 8, 6}, Version: Version{1, 21, 13},
+		Bug: &FixSummary{
+			Components: []template.HTML{"the <code>go</code> command", "the <code>covdata</code> command"},
+			Packages:   []string{"bytes"},
+		},
+	},
 	{
 		Date: Date{2024, 7, 2}, Version: Version{1, 22, 5},
 		Security: &FixSummary{