fix: use GITHUB_SHA instead of GITEA_SHA for artifact version

GITEA_SHA is not set in the runner container environment; GITHUB_SHA is.
Empty version string caused INVALID_ARGUMENT from Artifact Registry.

.gitea/workflows/ci-dev.yaml

@@ -173,7 +173,7 @@ jobs:
           gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
           gcloud config set project neuron-785695
 
-          VERSION="${GITEA_SHA:0:8}"
+          VERSION="${GITHUB_SHA:0:8}"
 
           gcloud artifacts generic upload \
             --repository=foundation-dev \

.gitea/workflows/ci-stage.yaml

@@ -183,7 +183,7 @@ jobs:
           gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
           gcloud config set project neuron-785695
 
-          VERSION="${GITEA_SHA:0:8}"
+          VERSION="${GITHUB_SHA:0:8}"
 
           gcloud artifacts generic upload \
             --repository=foundation-stage \

.gitea/workflows/sdk-release.yaml

@@ -299,7 +299,7 @@ jobs:
           gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
           gcloud config set project neuron-785695
 
-          VERSION="${GITEA_SHA:0:8}"
+          VERSION="${GITHUB_SHA:0:8}"
 
           gcloud artifacts generic upload \
             --repository=foundation-prod \