debian/rules: skip dh_strip on *.so (cross-compiled native libs)

When cross-compiling PostIt.Desktop for linux-arm64 from an amd64
runner container, the .deb ends up shipping HarfBuzzSharp.so and
SkiaSharp.so in ARM64 format. dh_strip invokes objcopy on every
file under debian/postit/, and objcopy on the amd64 host cannot
parse ARM64 .so files:

  objcopy: Unable to recognise the format of the input file
  `debian/postit/usr/lib/postit/libHarfBuzzSharp.so'
  dh_strip: error: ... returned exit code 1
  dh_strip: error: Aborting due to earlier error

Add --exclude=*.so to override_dh_strip. The upstream .so ships
with its own debug symbols; we don't lose anything by skipping
the strip on them.

Also drop the diag.yml workflow that diagnosed the initial
tag-not-found failure — no longer needed.

Discovered via the Forgejo Actions release.yml run on tag 1.0.6.

.forgejo/workflows/diag.yml

@@ -1,74 +0,0 @@
-name: diag
-
-# Diagnostic minimal : vérifie que le runner Forgejo démarre, qu'il
-# peut cloner, et qu'il a accès à Internet + Docker (pour le label
-# docker:// sur lequel tournent nos jobs).
-#
-# À supprimer une fois qu'on a confirmé que le runner est OK.
-
-on:
-  workflow_dispatch:
-
-jobs:
-  diag:
-    runs-on: docker
-    container:
-      image: docker.io/pazof/yavsc-build-env:debian12-dotnet10-android36-v2
-    steps:
-      - name: Hello
-        run: |
-          echo "Runner started, container is alive."
-          echo "Image: $(cat /etc/os-release | grep PRETTY_NAME)"
-          echo "Hostname: $(hostname)"
-          echo "User: $(whoami)"
-          echo "Working dir: $(pwd)"
-
-      - name: Network check
-        run: |
-          echo "--- DNS resolution ---"
-          getent hosts forgejo.pschneider.fr || echo "FAIL: cannot resolve forgejo.pschneider.fr"
-          echo "--- HTTP outbound ---"
-          curl -sS -o /dev/null -w "forgejo.pschneider.fr HTTP %{http_code} (%{time_total}s)\n" \
-            https://forgejo.pschneider.fr/ || echo "FAIL: cannot reach forgejo.pschneider.fr"
-          echo "--- Docker Hub ---"
-          curl -sS -o /dev/null -w "hub.docker.com HTTP %{http_code}\n" \
-            https://hub.docker.com/ || echo "FAIL: cannot reach hub.docker.com"
-
-      - name: Tooling check
-        run: |
-          echo "--- git ---"
-          git --version
-          echo "--- dotnet ---"
-          dotnet --info | head -5
-          echo "--- jq ---"
-          jq --version
-          echo "--- curl ---"
-          curl --version | head -1
-          echo "--- make ---"
-          make --version | head -1
-          echo "--- debhelper ---"
-          which dh || echo "FAIL: dh not found (debhelper absent)"
-          echo "--- imagemagick ---"
-          which convert || echo "FAIL: convert not found"
-
-      - name: Forgejo context probe
-        env:
-          FORGEJO_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
-        run: |
-          echo "--- forgejo.* context ---"
-          echo "forgejo.ref_name=[${{ forgejo.ref_name }}]"
-          echo "forgejo.repository=[${{ forgejo.repository }}]"
-          echo "forgejo.api_url=[${{ forgejo.api_url }}]"
-          echo "--- secrets.GITHUB_TOKEN probe ---"
-          if [[ -n "$FORGEJO_TOKEN" ]]; then
-            echo "FORGEJO_TOKEN is set (length=${#FORGEJO_TOKEN})"
-          else
-            echo "FORGEJO_TOKEN is EMPTY — secrets.GITHUB_TOKEN did not resolve"
-          fi
-          echo "--- API reachability via FORGEJO_TOKEN ---"
-          if [[ -n "$FORGEJO_TOKEN" ]]; then
-            HTTP=$(curl -sS -o /dev/null -w '%{http_code}' \
-              -H "Authorization: token $FORGEJO_TOKEN" \
-              "${{ forgejo.api_url }}/repos/${{ forgejo.repository }}")
-            echo "GET /repos/${{ forgejo.repository }} -> HTTP $HTTP"
-          fi

debian/rules

@@ -129,7 +129,20 @@ override_dh_shlibdeps:
 	dh_shlibdeps
 
 override_dh_strip:
-	dh_strip --exclude=.pdb
+	# --exclude=.pdb : .NET génère des .pdb même en Release, ils
+	# ne sont pas strippables proprement.
+	# --exclude=*.so  : Avalonia dépend de HarfBuzzSharp et SkiaSharp
+	# qui livrent leurs .so pré-compilés via NuGet (formats natifs
+	# multi-arch : linux-x64, linux-arm64, etc.). Quand on cross-
+	# compile depuis un hôte amd64 (build arm64), dh_strip appelle
+	# objcopy sur ces .so qui sont en ARM64 et objcopy natif amd64
+	# ne sait pas les lire :
+	#   objcopy: Unable to recognise the format of the input file
+	#   `debian/postit/usr/lib/postit/libHarfBuzzSharp.so'
+	# On les exclut donc du strip. Les symboles debug seront
+	# présents dans le .deb mais ce sont des libs upstream, pas
+	# notre code — pas critique.
+	dh_strip --exclude=.pdb --exclude=*.so
 
 
 define stage_postit