Получение текста из тега

можно использовать метод decompose

from bs4 import BeautifulSoup
import requests
URL = 'https://t-don.com/catalog/zapchasti-k-selhoztehnike/seyalki/atespar-turciya'
HEADERS = {'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.72 Safari/537.36', 'accept': '*/*'}


def get_html(url, params=None):
    r = requests.get(url, headers=HEADERS, params=params)
    return r


def get_content(html):
    soup = BeautifulSoup(html, 'html.parser')
    items = soup.find_all('div', class_='lst-itm')

    parts = []
    for item in items:
        item.find('p', class_='text-muted').select_one('span').decompose()
        parts.append({
            'title': item.find('a', class_='a-top').get_text(strip=True),
            'price': item.find('span', class_='cost-item').get_text(),
            'articul': item.find('p', class_='text-muted').get_text(),

        })
    print(parts)


def parse():
    html = get_html(URL)
    if html.status_code == 200:
        get_content(html.text)
    else:
        print('Error')


parse()

Если элементов больше чем один их надо удалять в цикле

from bs4 import BeautifulSoup

html = """
<p><span class="text-muted">Комплектность: </span><span class="label label-default"></span>Бандаж 1шт</p>
"""

test= BeautifulSoup(html, 'html.parser')
p = test.select_one('p')
for x in p.select('span'):
    x.decompose()
print(test)

from bs4 import BeautifulSoup as bs

txt = r'<p class="text-muted"><span>Артикул:</span>08.01.13</p>'

soup = bs(txt, "html.parser")
print(soup.text.split(':')[1])