Closes gh-16272

Closes gh-16273

* gh-16270:
  Use HTTPS for external links in XML files

See gh-16270

* pr/16269:
  Use the latest DTD declaration for Checkstyle

Closes gh-16269

* pr/16265:
  Remove explicit types

Closes gh-16265

Closes gh-16033

Closes gh-16229

* gh-16247:
  Update build and setup configuration to use HTTPS

Closes gh-16247

See gh-16247

* gh-16246:
  Polish "Update build and setup configuration to use HTTPS"
  Update build and setup configuration to use HTTPS

Closes gh-16246

See gh-16246

See gh-16246

* gh-16245:
  Polish "Update build and setup configuration to use HTTPS"
  Update build and setup configuration to use HTTPS

Closes gh-16245

See gh-16245

See gh-16245

* gh-16244:
  Polish "Update build and setup configuration to use HTTPS"
  Update build and setup configuration to use HTTPS

Closes gh-16244

See gh-16244

See gh-16244

* gh-16243:
  Polish "Update build and setup configuration to use HTTPS"
  Update build and setup configuration to use HTTPS

Closes gh-16243

See gh-16243

See gh-16243

* pr/16263:
  Add missing "to" in GitHub SUPPORT file

Closes gh-16263

Closes gh-16211

* pr/15982:
  Polish "Fix request factory used with withBasicAuth"
  Fix request factory used with TestRestTemplate withBasicAuth