refactor: improve code quality and efficiency in various files (#548)

- Replace loadConfig() with _ = loadConfig()
- Update file permissions from 0660 to 0o660
- Simplify variable declarations
- Replace golang.org/x/crypto/ssh/terminal with golang.org/x/term
- Remove unused getCertPrincipals function
- Replace time.Now().Sub() with time.Since()
- Add test for ArgToIndex function

Signed-off-by: appleboy <appleboy.tw@gmail.com>

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-on: https://gitea.com/gitea/tea/pulls/548
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: techknowlogick <techknowlogick@noreply.gitea.io>
Co-authored-by: appleboy <appleboy.tw@gmail.com>
Co-committed-by: appleboy <appleboy.tw@gmail.com>

modules/utils/parse_test.go

@@ -0,0 +1,48 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package utils
+
+import "testing"
+
+func TestArgToIndex(t *testing.T) {
+	tests := []struct {
+		name    string
+		arg     string
+		want    int64
+		wantErr bool
+	}{
+		{
+			name:    "Valid argument",
+			arg:     "#123",
+			want:    123,
+			wantErr: false,
+		},
+		{
+			name:    "Invalid argument",
+			arg:     "abc",
+			want:    0,
+			wantErr: true,
+		},
+		{
+			name:    "Empty argument",
+			arg:     "",
+			want:    0,
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ArgToIndex(tt.arg)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ArgToIndex() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("ArgToIndex() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}