internal/history: document future Go 1.20.4 and 1.19.9 releases

Change-Id: I5fc471002322935129de27c4ec8407defccb26ff
Reviewed-on: https://go-review.googlesource.com/c/website/+/490375
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
diff --git a/internal/history/release.go b/internal/history/release.go
index c603535..024f1b2 100644
--- a/internal/history/release.go
+++ b/internal/history/release.go
@@ -15,6 +15,24 @@
 // The table is sorted by date, breaking ties with newer versions first.
 var Releases = []*Release{
 	{
+		Date: Date{2023, 5, 2}, Version: Version{1, 20, 4},
+		Future:   true,
+		Security: &FixSummary{Components: []template.HTML{"the standard library"}},
+		Bug: &FixSummary{
+			Components: []template.HTML{"the compiler", "the runtime"},
+			Packages:   []string{"crypto/subtle", "crypto/tls", "net/http", "syscall"},
+		},
+	},
+	{
+		Date: Date{2023, 5, 2}, Version: Version{1, 19, 9},
+		Future:   true,
+		Security: &FixSummary{Components: []template.HTML{"the standard library"}},
+		Bug: &FixSummary{
+			Components: []template.HTML{"the compiler", "the runtime"},
+			Packages:   []string{"crypto/tls", "syscall"},
+		},
+	},
+	{
 		Date: Date{2023, 4, 4}, Version: Version{1, 20, 3},
 		Security: &FixSummary{Packages: []string{"go/parser", "html/template", "mime/multipart", "net/http", "net/textproto"}},
 		Bug: &FixSummary{