Since the Bootstrap 5 migration the "headings" `<h1>`, `<h2>`, ... are
smaller than before.
This commit, restores the old CSS rules from Bootstrap 4 for reports.
Steps to reproduce:
* Open Sales
* Select a quotation
* Print the Quotation (using Print dropdown) => BUG title is smaller
than the old version of Odoo (e.g. Odoo v15)
closesodoo/odoo#106721
X-original-commit: 76299a8d63e85249d30d864a777c2f142ea5daf5
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>