ScanCode killed within Docker container

### Description

While analyzing some applications with the dockerized scancode, the scancode process is unexpectedly killed during the scan phase without any generated report:

```
./scancode: line 123: 16 Killed "$SCANCODE_ROOT_DIR/bin/scancode" "$@"
```

I have had this issue with different apps that I have been able to analyze without problem with previous versions of ScanCode. I suspect the timeout handling to be a bit too radical.

Any help to get the reports generated would be appreciated!

### How To Reproduce

a) Build the ScanCode docker image following the [official instructions](https://scancode-toolkit.readthedocs.io/en/latest/getting-started/install.html#installation-via-docker) using the "[Source code (zip)](https://github.com/nexB/scancode-toolkit/archive/refs/tags/v21.8.4.zip)" provided with the [v21.8.4 release](https://github.com/nexB/scancode-toolkit/releases/tag/v21.8.4).

b) Download and extract the [source code](https://github.com/hudson/hudson-2.x/archive/refs/heads/master.zip) of "hudson-2.x" as example application.

c) Start the analysis
```
docker run -v /Users/maarc/download/hudson_2_src/:/hudson_2_src scancode-toolkit -l -p -c --html-app /hudson_2_src/index.html /hudson_2_src --verbose -n 10 --timeout 0 --only-findings --ignore /test --ignore /tests --ignore *.jmx --ignore *.sha1 --ignore *.git --ignore *.mvn
```

d) You will get after a while:

```
Setup plugin: scan:licenses...
Setup plugin: scan:copyrights...
Setup plugin: scan:packages...
Setup plugin: output:html-app...
Collect file inventory...
Scan files for: licenses, copyrights, packages with 10 process(es)...
Scanned: /hudson_2_src/hudson-2.x-master/.hudson
[...]
Scanned: /hudson_2_src/hudson-2.x-master/hudson-core/src/main/resources/hudson/scm/SCM/project-changes.jelly
./scancode: line 123: 16 Killed "$SCANCODE_ROOT_DIR/bin/scancode" "$@"
```

### System configuration

* What OS are you running on? (Windows/MacOS/Linux)
MacOS

* What version of scancode-toolkit was used to generate the scan file?
v21.8.4 from the release page

* What installation method was used to install/run scancode? (pip/source download/other)
Built my own Docker container following the official instructions.