internal/history: document Go 1.26.5 and 1.25.12 releases

Change-Id: Iee462566e8700bae65dc92e430dda5644460e42f
Reviewed-on: https://go-review.googlesource.com/c/website/+/797680
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Auto-Submit: David Chase <drchase@google.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

internal/history/release.go

diff --git a/internal/history/release.go b/internal/history/release.go
index 9926d42..632a510 100644
--- a/internal/history/release.go
+++ b/internal/history/release.go
@@ -14,6 +14,46 @@
 // The table is sorted by date, breaking ties with newer versions first.
 var Releases = []*Release{
 	{
+		Date: Date{2026, 7, 7}, Version: Version{1, 26, 5},
+		Security: &FixSummary{
+			Packages: []string{
+				"crypto/tls",
+				"os",
+			},
+		},
+		Bug: &FixSummary{
+			Components: []template.HTML{
+				"the compiler",
+				"the runtime",
+				"the <code>go</code> command",
+			},
+			Packages: []string{
+				"net",
+				"os",
+				"syscall",
+			},
+		},
+	},
+	{
+		Date: Date{2026, 7, 7}, Version: Version{1, 25, 12},
+		Security: &FixSummary{
+			Packages: []string{
+				"crypto/tls",
+				"os",
+			},
+		},
+		Bug: &FixSummary{
+			Components: []template.HTML{
+				"the compiler",
+				"the <code>go</code> command",
+			},
+			Packages: []string{
+				"net",
+				"os",
+			},
+		},
+	},
+	{
 		Date: Date{2026, 6, 2}, Version: Version{1, 26, 4},
 		Security: &FixSummary{
 			Packages: []string{