Update bundled pip to 26.1.1

[sbidoul]

Feature or enhancement

Proposal:

Pip 26.1.1 was released.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-149377: update bundled pip to 26.1.1 #149378
• [3.14] gh-149377: update bundled pip to 26.1.1 (GH-149378) #149379
• [3.13] gh-149377: update bundled pip to 26.1.1 (GH-149378) #149380

[hugovk]

Thank you, just in time for 3.15 beta 1 tomorrow :)