Auto merge of #20841 - aneeshusa:increase-taskcluster-runtime, r=jdm

Increase taskcluster runtime

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Based on the Taskcluster log for
(https://taskcluster-artifacts.net/HkxDh1oKQceXH1fL9RSGow/0/public/logs/live_backing.log),
it looks like the job is running successfully but hitting the max time limit.

Our builds + tests shouldn't take this long to run normally,
but we'll need to set up sccache with cache uploading/downloading
in order to improve most build times.

For now, bump the max run time to 2 hours;
since we complete one build + som tests within an hour,
2 hours should be enough for the second build to finish as well.

Also, add `set -x` for easier debugging.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because they are trying to fix the testing infra

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.taskcluster.yml

@@ -16,7 +16,7 @@ tasks:
           - pull_request.reopened
           - pull_request.synchronize
     payload:
-      maxRunTime: 3600
+      maxRunTime: 7200
       image: 'servobrowser/servo-linux-dev:servo-linux-build-deps-2017-06-30'
       command:
         - /bin/bash

etc/ci/taskcluster-test.sh

@@ -8,6 +8,8 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
+set -x
+
 curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain none -y
 export PATH="${HOME}/.cargo/bin:${PATH}"