fix: work around golang/go#61888

.version

@@ -1 +1 @@
-0.2.525
+0.2.528

cmd/templ/generatecmd/main.go

@@ -524,7 +524,11 @@ func logWithDecoration(w io.Writer, decoration string, col color.Attribute, form
 }
 
 // Replace "go 1.21.3" with "go 1.21" until https://github.com/golang/go/issues/61888 is fixed, see templ issue https://github.com/a-h/templ/issues/355
-var goVersionRegexp = regexp.MustCompile(`\ngo (\d+\.\d+)\.\d+\n`)
+var goVersionRegexp = regexp.MustCompile(`\ngo (\d+\.\d+)(?:\D.+)\n`)
+
+func patchGoVersion(moduleFileContents []byte) []byte {
+	return goVersionRegexp.ReplaceAll(moduleFileContents, []byte("\ngo $1\n"))
+}
 
 func checkTemplVersion(dir string) error {
 	// Walk up the directory tree, starting at dir, until we find a go.mod file.
@@ -556,7 +560,7 @@ func checkTemplVersion(dir string) error {
 		}
 
 		// Replace "go 1.21.x" with "go 1.21".
-		m = goVersionRegexp.ReplaceAll(m, []byte("\ngo $1\n"))
+		m = patchGoVersion(m)
 
 		mf, err := modfile.Parse(current, m, nil)
 		if err != nil {

cmd/templ/generatecmd/main_test.go

@@ -0,0 +1,56 @@
+package generatecmd
+
+import (
+	"testing"
+
+	"golang.org/x/mod/modfile"
+)
+
+func TestPatchGoVersion(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{
+			input:    "go 1.20",
+			expected: "1.20",
+		},
+		{
+			input:    "go 1.20.123",
+			expected: "1.20",
+		},
+		{
+			input:    "go 1.20.1",
+			expected: "1.20",
+		},
+		{
+			input:    "go 1.20rc1",
+			expected: "1.20",
+		},
+		{
+			input:    "go 1.15",
+			expected: "1.15",
+		},
+		{
+			input:    "go 1.15-something-something",
+			expected: "1.15",
+		},
+		{
+			input:    "go 1.23.23.23",
+			expected: "1.23",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.input, func(t *testing.T) {
+			input := "module github.com/a-h/templ\n\n" + string(test.input) + "\n"
+			actual := patchGoVersion([]byte(input))
+			mf, err := modfile.Parse("go.mod", actual, nil)
+			if err != nil {
+				t.Errorf("failed to parse go.mod: %v", err)
+			}
+			if test.expected != mf.Go.Version {
+				t.Errorf("expected %q, got %q", test.expected, mf.Go.Version)
+			}
+		})
+	}
+}