encoding.csv: fix reading when there is no line ending at the end of the file (fix #22337) (#22342)

vlib/encoding/csv/csv_reader_eol_test.v

@@ -0,0 +1,34 @@
+import encoding.csv
+
+fn test_no_ending() {
+	data := 'x,y,d
+a,b
+w'
+	mut parser := csv.new_reader(data)
+	mut arr := []string{}
+	for {
+		items := parser.read() or { break }
+		arr << items.join('-')
+	}
+	dump(arr)
+	assert arr[0].str() == 'x-y-d'
+	assert arr[1].str() == 'a-b'
+	assert arr[2].str() == 'w'
+}
+
+fn test_with_ending() {
+	data := 'x,y,d
+a,b
+w
+'
+	mut parser := csv.new_reader(data)
+	mut arr := []string{}
+	for {
+		items := parser.read() or { break }
+		arr << items.join('-')
+	}
+	dump(arr)
+	assert arr[0].str() == 'x-y-d'
+	assert arr[1].str() == 'a-b'
+	assert arr[2].str() == 'w'
+}