ci: doc-build: increase timeout for doc build jobs

With the introduction of the new runners, the time it takes to build the
documentation in CI has slowed down to the point that the job often times
out.

Applied a conservative 2x factor to the timeouts that were in place.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

.github/workflows/doc-build.yml

@@ -59,7 +59,7 @@ jobs:
         ( needs.doc-file-check.outputs.file_check == 'true' || github.event_name != 'pull_request' )
     runs-on:
       group: zephyr-runner-v2-linux-x64-4xlarge
-    timeout-minutes: 45
+    timeout-minutes: 90
     concurrency:
       group: doc-build-html-${{ github.ref }}
       cancel-in-progress: true
@@ -186,7 +186,7 @@ jobs:
     runs-on:
       group: zephyr-runner-v2-linux-x64-4xlarge
     container: texlive/texlive:latest
-    timeout-minutes: 60
+    timeout-minutes: 120
     concurrency:
       group: doc-build-pdf-${{ github.ref }}
       cancel-in-progress: true