HDF5 cross-platform compatibility of attributes

**Describe the bug**
Some HDF5 Datasets written on x86 platforms cannot be opened on ARM and PowerPC architectures.

**To Reproduce**

Use either:
[Be_dens.zip](https://github.com/openPMD/openPMD-api/files/10467642/Be_dens.zip)

or:
https://github.com/openPMD/openPMD-example-datasets/blob/draft/example-femm-3d.h5

and try opening it on a PowerPC system (e.g. Summit) or an ARM system (e.g. modern Apple devices) with `openpmd-ls`.

**Expected behavior**

```
> openpmd-ls Be_dens.h5
openPMD series: Be_dens
openPMD standard: 1.1.0
openPMD extensions: 0

data author: ...
data created: 2023-01-04 15:19:57 +0100
data backend: HDF5
generating machine: unknown
generating software: MALA (version: 1.1.0)
generating software dependencies: unknown

number of iterations: 1 (groupBased)
all iterations: 0

number of meshes: 1
all meshes:
Density

number of particle species: 1
all particle species:
atoms
```

**Actual behavior**
```
> openpmd-ls ../Be_dens.h5
openPMD series: Be_dens
openPMD standard: 1.1.0
openPMD extensions: 0

data author: ...
data created: 2023-01-04 15:19:57 +0100
data backend: HDF5
generating machine: unknown
generating software: MALA (version: 1.1.0)
generating software dependencies: unknown

number of iterations: 1 (groupBased)
all iterations: [AbstractIOHandlerImpl] IO Task READ_ATT failed with exception. Removing task from IO queue and passing on the exception.
An error occurred while opening the specified openPMD series!
[HDF5] Unsupported simple attribute type
```

**Software Environment**
Recent conda, pip installs.

**Additional context**
Add any other context about the problem here.