take the artifact action from a fork of our own

Upstream v4 refuses to run anywhere but github.com: it reads
GITHUB_SERVER_URL, calls everything else a GitHub Enterprise Server and
throws before making a request. A probe run settled the rest — the name
cannot be overridden from a step, because the runner sets the GITHUB_
ones last. So the action now comes from this Gitea, forked with that one
check removed, on a fixed tag rather than a floating one.

.gitea/workflows/release.yml

@@ -140,17 +140,20 @@ jobs:
 
       # The artifact is where the package waits to be uploaded to Partner Center.
       #
-      # GITHUB_SERVER_URL is put back to github.com for these two steps alone.
+      # The action comes from this Gitea rather than from github.com, and it is
-      # The action reads it to tell a GitHub Enterprise Server from github.com
+      # a fork of actions/upload-artifact with one line changed. Upstream reads
-      # and refuses to run on anything else with a GHESNotSupportedError, Gitea
+      # GITHUB_SERVER_URL, takes every host but github.com and its enterprise
-      # included — although Gitea answers the very requests the action makes.
+      # ones for a GitHub Enterprise Server — where the v4 artifact backend does
-      # The upload goes to ACTIONS_RESULTS_URL, which is left as Gitea set it,
+      # not exist — and throws before it makes a request. Here that backend does
-      # so the substitution reaches the check and nothing else. The artifact-url
+      # exist and answers, but the check runs on the runner ahead of the network
-      # output comes out pointing at github.com; nothing here reads it
+      # and never lets it prove itself; nor can the name be corrected from this
+      # file, as the runner sets the GITHUB_ ones over the env of a step. The
+      # fork carries the reasoning in full in its GITEA-PATCH.md.
+      #
+      # The tag is a fixed one. A floating tag is how this broke before: the
+      # action is fetched at run time, and what arrives can change on its own
       - name: Keep the package
-        uses: actions/upload-artifact@v4
+        uses: https://git.alrakis.kz/actions/upload-artifact@v4-gitea
-        env:
-          GITHUB_SERVER_URL: https://github.com
         with:
           name: msix-${{ steps.version.outputs.version }}
           path: artifacts/packages/
@@ -159,9 +162,7 @@ jobs:
       # The .wixpdb next to each installer is left out on purpose: it is of use
       # only when something has to be traced back to the WiX source
       - name: Keep the installer
-        uses: actions/upload-artifact@v4
+        uses: https://git.alrakis.kz/actions/upload-artifact@v4-gitea
-        env:
-          GITHUB_SERVER_URL: https://github.com
         with:
           name: installer-${{ steps.version.outputs.plain }}
           path: artifacts/installers/*.msi