Fix Linux artifact upload paths to match actual JUCE output layout

JUCE places Linux build output under
build/plugins/<name>/<name>_artefacts/Release/{VST3,LV2,Standalone}/
The upload globs were missing the plugins/<name>/ and Release/ layers,
so no files were ever found. Switched to build/**/Release/ globs which
match regardless of the intermediate plugin subdirectory.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Noizefield

.github/workflows/build-pr.yml

@@ -190,9 +190,9 @@ jobs:
         with:
           name: linux-${{ matrix.plugin }}-pr
           path: |
-            build/*_artefacts/*.vst3
-            build/*_artefacts/*.lv2
-            build/*_artefacts/${{ matrix.plugin }}
+            build/**/Release/VST3/
+            build/**/Release/LV2/
+            build/**/Release/Standalone/${{ matrix.plugin }}
           retention-days: 7
 
   # ============================================

.github/workflows/build-release.yml

@@ -161,9 +161,9 @@ jobs:
         with:
           name: linux-${{ inputs.plugin_name }}
           path: |
-            build/*_artefacts/*.vst3
-            build/*_artefacts/*.lv2
-            build/*_artefacts/${{ inputs.plugin_name }}
+            build/**/Release/VST3/
+            build/**/Release/LV2/
+            build/**/Release/Standalone/${{ inputs.plugin_name }}
           retention-days: 30
 
   # ============================================