p-buttongroup with labeled and icon only : icon only is not full height

[LouLeGrain]

Describe the bug

Happens on most recent version of PrimeNG 19.0.9

See stackblitz for full repro

Code used :

  <p-buttongroup>
    <p-button 
      severity="success" 
      label="Save" 
      icon="pi pi-save">
    </p-button>
    <p-button
      severity="warn"
      icon="pi pi-refresh"
      pTooltip="reset">
    </p-button>
  </p-buttongroup>

Pull Request Link

No response

Reason for not contributing a PR

• Lack of time
• Unsure how to implement the fix/feature
• Difficulty understanding the codebase
• Other

Other Reason

No response

Reproducer

https://stackblitz.com/edit/7wccw74u?file=src%2Fapp%2Fbutton-group-demo.html

Environment

package.json

{
  "name": "primeng-button-group-demo",
  "description": "PrimeNG ButtonGroupDemo",
  "license": "MIT",
  "keywords": [],
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test"
  },
  "dependencies": {
    "@angular/animations": "^19.0.1",
    "@angular/cdk": "~19.0.1",
    "@angular/cli": "^19.2.1",
    "@angular/common": "^19.0.1",
    "@angular/compiler": "^19.0.1",
    "@angular/core": "^19.0.1",
    "@angular/forms": "^19.0.1",
    "@angular/platform-browser": "^19.0.1",
    "@angular/platform-browser-dynamic": "^19.0.1",
    "@angular/router": "^19.0.1",
    "@primeng/themes": "^19.0.0",
    "@types/jasmine": "4.3.1",
    "@types/node": "12.20.55",
    "chart.js": "^3.3.2",
    "primeicons": "7.0.0",
    "primeng": "^19.0.0",
    "quill": "1.3.7",
    "rxjs": "~7.8.1",
    "tslib": "^2.5.0",
    "zone.js": "~0.15.0"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "^19.0.2",
    "@angular/cli": "^19.0.1",
    "@angular/compiler-cli": "^19.0.1",
    "@angular/language-service": "~16.2.0",
    "@types/jasmine": "~4.3.1",
    "@types/node": "^16.18.67",
    "codelyzer": "^0.0.28",
    "jasmine-core": "~4.6.0",
    "karma": "~6.4.2",
    "karma-chrome-launcher": "~3.2.0",
    "karma-coverage": "~2.2.0",
    "karma-jasmine": "~5.1.0",
    "karma-jasmine-html-reporter": "~2.0.0",
    "ts-node": "~8.3.0",
    "typescript": "~5.5.4"
  }
}

Angular version

19.0.1

PrimeNG version

v19

Node version

No response

Browser(s)

No response

Steps to reproduce the behavior

Put two buttons inside

Expected behavior

Both buttons should take the same height