fix(kernel_crawler): fix photonOS kernelrelease, stripping ".$arch" substring

[FedeDP]

What type of PR is this?

/kind bug

Any specific area of the project related to this PR?

/area crawler

What this PR does / why we need it:

PhotonOS kernel packages have a ".$arch" suffix, thus our kernelrelease is different from uname -r output.
Fix this by manually removing the suffix.
Example:

• uname -r -> 6.1.53-1.ph5
• kernelrelease -> 6.1.53-1.ph5.x86_64

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

[FedeDP]

/cc @zuc @maxgio92

[FedeDP]

Example output now:

X86_64:
{
      "kernelversion": "1",
      "kernelrelease": "6.1.45-6.ph5",
      "target": "photon",
      "headers": [
        "https://packages.vmware.com/photon/5.0/photon_5.0_x86_64/x86_64/linux-secure-devel-6.1.45-6.ph5.x86_64.rpm"
      ]
}

aarch64:
{
      "kernelversion": "1",
      "kernelrelease": "6.1.56-6.ph5",
      "target": "photon",
      "headers": [
        "https://packages.vmware.com/photon/5.0/photon_updates_5.0_aarch64/aarch64/linux-devel-6.1.56-6.ph5.aarch64.rpm"
      ]
}