HM-5952 Add mount-s3 to misc-debs for Hyperscale S3 FUSE driver

[kautilya-perforce]

Summary

• Adds mount-s3_1.22.3_amd64.deb to the misc-debs package's debs array in packages/misc-debs/config.sh
• mount-s3 (Mountpoint for Amazon S3) has no apt repository — Amazon distributes it only as a direct .deb download from S3, so it fits the misc-debs pattern

Pre-requisite (manual step before this PR can build)

Upload the deb to Artifactory:

• Path: linux-pkg/misc-debs/mount-s3_1.22.3_amd64.deb
• SHA256: 259a793b1233258b35ce5ce902df177393542fd76dd2a606f07e800e28591df6
• Source: https://s3.amazonaws.com/mountpoint-s3-release/latest/x86_64/mount-s3.deb

cc @prakashsurya — following your suggestion on appliance-build#872 to use misc-debs.

Context

Part of HM-5952 (bundle mount-s3 and blobfuse2 FUSE drivers into the Delphix closed appliance image for the Hyperscale Snowflake connector). OSRB tracking: DLPXECO-13872.

Three PRs total:

1. devops-gate PR #4503 — vendor blobfuse2 PPA into mirror
2. This PR — add mount-s3 to misc-debs
3. appliance-build PR #872 — Ansible tasks to install both drivers (exclusion to be reverted once both packages are in mirror)

Test plan

• Upload mount-s3_1.22.3_amd64.deb to Artifactory at the path above
• Run ./buildpkg.sh misc-debs on a noble build VM and confirm mount-s3 deb appears in artifacts
• Verify SHA256 matches after fetch

🤖 Generated with Claude Code

[prakashsurya]

Kicked off a pre-push appliance build/test run (with `misc-debs` built):

https://selfservice-jenkins.eng-tools-prd.aws.delphixcloud.com/job/appliance-build-orchestrator-pre-push/14296/

[dbjwhs-perforce]

LGTM.

The upgrade-testing failure on Prakash's run (appliance-build-orchestrator-pre-push #14296) is unrelated to this change. The test engine VM went unreachable mid-run: HTTP to /resources/json/delphix/session and SSH both hit connect timeouts on dlpx-qa-2026400-bb-chain-9358-...dlpxdc.co, so qarunner exited 1 and "Publish build results" then couldn't collect the svc-logs bundle. That's an environment flake. A FUSE-driver .deb sitting in the image can't make a VM stop answering HTTP and SSH during an upgrade.

More to the point, that run actually exercised and passed the pieces that matter for this PR:

#14296 orchestrator                FAILURE
  Build Necessary Packages         SUCCESS   <- misc-debs built, mount-s3 fetched + SHA256 OK
  Build Appliance                  SUCCESS   <- image built with mount-s3
  Import to DCenter                SUCCESS
  Run Tests (parallel)             FAILED
     dx-integration-tests #34271   SUCCESS   <- functional suite passed
     upgrade-testing #4508         FAILURE
        blackbox-chained #9358     FAILURE
           Run Blackbox links      SUCCESS
           Publish build results   FAILED

misc-debs built with the mount-s3 deb (SHA256 verified), the appliance built and imported, and the functional suite passed. Worth re-running upgrade-testing to get a clean green for the record, but the flake shouldn't block this.