fix: make /lib/modules directory overlayfs over the hostpath

[rugggger]

TL;DR

Implemented overlayfs for /lib/modules to support driver loading on read-only host mounts.

What changed?

• Added a new setup_overlayfs_for_lib_modules() function in weka_runtime.py that creates a writable overlay filesystem for /lib/modules using tmpfs
• The overlay allows writing to /lib/modules even when the host mount is read-only
• Integrated this function into the driver loading workflow
• Refactored driver dependencies code into a separate file (drivers.go) for better organization
• Made /lib/modules mount read-only in non-COS environments

<release_notes>

Driver Loading on Read-Only Systems

Type: fix
Enabled driver loading even when the host's /lib/modules directory is mounted as read-only, by utilizing an overlay filesystem. This resolves issues with driver loading in environments where the host /lib/modules is read-only.
</release_notes>

[rugggger]

• fix: refactor hugepages logic to its own file #1998
• fix: make /lib/modules directory overlayfs over the hostpath #1997 👈 (View in Graphite)
• main

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[graphite-app]

Graphite Automations

"Add anton/matt/sergey/kristina as reviwers on operator PRs" took an action on this PR • (12/23/25)

3 reviewers were added to this PR based on Anton Bykov's automation.

[graphite-app]

Merge activity

• Dec 23, 1:25 PM UTC: rugggger added this pull request to the Graphite merge queue.
• Dec 23, 1:25 PM UTC: CI is running for this pull request on a draft pull request (#2004) due to your merge queue CI optimization settings.
• Dec 23, 2:05 PM UTC: Merged by the Graphite merge queue via draft PR: #2004.