ci: publish both packages to a single helexa/helexa COPR project

Consolidates the previous helexa/cortex and helexa/helexa-neuron COPR
projects into one shared project. Hosts enable a single repo and get
access to both packages — cortex for gateway hosts and helexa-neuron
for GPU nodes. Reduces the "which copr do I enable on this host"
friction, and makes it clear the two packages are parts of the same
helexa project suite.

CI keeps two independent publish jobs (copr-cortex and copr-neuron)
running in parallel; they now both target helexa/helexa with their
respective SRPMs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -192,7 +192,7 @@ jobs:
       - name: Publish to COPR
         uses: https://git.lair.cafe/actions/copr-publish@v1
         with:
-          project: helexa/cortex
+          project: helexa/helexa
           srpm: "*.src.rpm"
           copr-config: ${{ secrets.COPR_CONFIG }}
 
@@ -209,7 +209,7 @@ jobs:
       - name: Publish to COPR
         uses: https://git.lair.cafe/actions/copr-publish@v1
         with:
-          project: helexa/helexa-neuron
+          project: helexa/helexa
           srpm: "*.src.rpm"
           copr-config: ${{ secrets.COPR_CONFIG }}