fix(gha): update role to assume

[LucaGuerra]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

Any specific area of the project related to this PR?

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/area build

What this PR does / why we need it:

Update GHA workflow to use this repository's role (see: https://github.com/falcosecurity/test-infra/pull/1237)

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Issif, LucaGuerra

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/falcosecurity/falcosidekick-ui/blob/master/OWNERS)~~ [Issif] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[poiana]

LGTM label has been added.

Git tree hash: 84dd4994432ab4b060d842ee7eb5ea82f97489a5