lang: core: Remove the unnecessary func suffix

We don't really need these, it's clear what things are.

lang/core/datetime/format_test.go

@@ -0,0 +1,52 @@
+// Mgmt
+// Copyright (C) 2013-2024+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+//go:build !darwin
+
+package coredatetime
+
+import (
+	"context"
+	"testing"
+
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+func TestFormat(t *testing.T) {
+	inputVal := &types.IntValue{V: 1443158163}
+	inputFormat := &types.StrValue{V: "2006"}
+
+	val, err := Format(context.Background(), []types.Value{inputVal, inputFormat})
+	if err != nil {
+		t.Error(err)
+	}
+	if val.String() != `"2015"` {
+		t.Errorf("invalid output, expected %s, got %s", `"2015"`, val.String())
+	}
+}