Optimize Dockerfile install layer for test_suite

[rauldsl]

Description:

• Combined update and install into one step for consistency
• Added cache cleanup (rm -rf /var/cache/dnf) to reduce final image size
• Improved readability with multi-line formatting
• These changes reduce image size and make maintenance easier without changing functionality.

[rauldsl]

Hey @evgenyz
I noticed you reviewed a PR.
Would you be the appropriate reviewer for this one, or should I add someone else?

[rauldsl]

Tks @evgenyz