[CI][Security] ROCM-26573: Move secrets from argv to env variables

[vkallesh]

Fix for https://amd-hub.atlassian.net/browse/ROCM-26573 - Plaintext HTTP Auth Token Transmission and Secrets Exposed on Process argv

Issue: buildbot-psdb-trigger.yml and compute-rocm-dkmd-afar-trigger.yml
pass secrets directly on the shell command line (argv), making them
visible to any process that can read /proc/<pid>/cmdline or tools like
ps, top, htop. Additionally, Buildbot API calls used HTTP instead of
HTTPS, exposing credentials to network observers.

Impact: Secrets (BUILDBOT_USER, BUILDBOT_PWD, CI_JENKINS_TOKEN) are
visible in process listings, shell history, and system monitoring tools.
HTTP transmission allows MITM attacks and credential interception.

Fix:
1. Move all secrets from argv to env: blocks
2. Pass secrets to docker containers via -e flags
3. Access secrets via $ENV_VAR in shell, os.environ in Python
4. Change all Buildbot HTTP URLs to HTTPS (lines 86, 93)
5. Remove echo of BUILDBOT_HOST:PORT (information disclosure)

Files modified:
- .github/workflows/buildbot-psdb-trigger.yml
  * Moved BUILDBOT_USER, BUILDBOT_PWD, BUILDBOT_HOST, BUILDBOT_WORKER_PORT to env:
  * Changed http:// to https:// for Buildbot API calls * Removed echo of secrets

- .github/workflows/compute-rocm-dkmd-afar-trigger.yml
   * Moved CI_JENKINS_USER, ROCM_JENKINS_CI_TOKEN to env: 
   * Access via os.environ[] instead of workflow substitution