desktop.yml: every job has its own deadline (#5409)

Run 8830's Linux bundle sat on a rust-lld link whose 17 threads were all
parked on futexes until the runner's own 30-minute cap ended it. verify, the
Linux and Windows builds get 20 minutes (warm runs take ~4, and a cold one
compiles the tree in about two), the manifest 5. Kept under the runner's cap
so these are the limits that fire.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.forgejo/workflows/desktop.yml

@@ -91,6 +91,7 @@ jobs:
   verify:
     name: Web tests, clippy, Rust tests and rustfmt
     needs: [decide]
+    timeout-minutes: 20
     if: needs.decide.outputs.build == 'true'
     runs-on: python-ci
     container:
@@ -146,6 +147,11 @@ jobs:
   build:
     name: Tauri desktop (Linux)
     needs: [decide, verify]
+    # A deadline, not a budget: warm builds take ~4 minutes. Without one a hung step
+    # runs to the runner's own 30-minute cap, as run 8830 did on a rust-lld link whose
+    # threads had all deadlocked (#5409). Kept under that cap so this one is the limit
+    # that fires, whatever the runner is configured with.
+    timeout-minutes: 20
     if: needs.decide.outputs.build == 'true'
     runs-on: python-ci
     container:
@@ -339,6 +345,7 @@ jobs:
   windows:
     name: Windows installer (cross-compiled)
     needs: [decide, verify]
+    timeout-minutes: 20
     if: needs.decide.outputs.build == 'true'
     runs-on: python-ci
     container:
@@ -471,6 +478,7 @@ jobs:
   manifest:
     name: Update manifest
     needs: [build, windows]
+    timeout-minutes: 5
     if: github.ref == 'refs/heads/dev' || github.ref == 'refs/heads/main'
     runs-on: python-ci
     container: