[shim] Fix `DCGMWrapperInterface` nil check (dstackai#2980)

Fixes: dstackai#2979

[Nebius] Support spot instances and B200 (dstackai#2965)

* [Nebius] Support spot instances and B200 dstackai#2954

* [Nebius] Ensure the SDK supports spot instances

[Nebius] Support spot instances and B200 (dstackai#2965)

* [Nebius] Support spot instances and B200 dstackai#2954

* [Nebius] Ensure the SDK supports spot instances

[Internal]: Fix release workflow (dstackai#2959)

Port changes from dstackai#2936 and dstackai#2952

Fix Cron syntax typo

[UI] Fix logs loading dstackai#2892 (dstackai#2920)

* [UI] Fix logs loading dstackai#2892

* [UI] Fix logs loading dstackai#2892

Return logs in base64 for backward compatibility (dstackai#2910)

* Return logs in base64 for backward compatibility

* Fix newlines in logs UI

* Fix lint

* Fix lint

Switch to `e2-medium` for GCP gateways (dstackai#2886)

Switching from `e2-small` to `e2-medium` decreases
provisioning time from about 5 minutes to about 2
minutes. The bottleneck is the snap, apt, and pip
package installation, which takes too long on
`e2-small`, likely because of the burstable CPU -
`e2-small` comes with 0.5-2 vCPU, while
`e2-medium` comes with 1-2 vCPU, depending on the
burst.

Fix update project required permissions (dstackai#2846)