Borg2 complains about extended attributes, when importing Solaris TAR archives

## Have you checked borgbackup docs, FAQ, and open GitHub issues?

Yes

## Is this a BUG / ISSUE report or a QUESTION?

Bug

## System information. For client/server mode post info for both machines.

#### Your borg version (borg -V).
```
borg 2.0.0b12
```

#### Operating system (distribution) and version.
Ubuntu 22.04.5 (ARM64)

#### Hardware / network configuration, and filesystems used.

#### How much data is handled by borg?
Around 100KB

#### Full borg commandline that lead to the problem (leave away excludes and passwords)
```
borg import-tar --list --info -r BX2 SolarisEAs_FIFO_SymLink Download/SolarisEAs_FIFO_SymLink.tar
```

## Describe the problem you're observing.
When trying to import some test TAR archives, created under Solaris 10, I receive the following, regarding the extended attributes contained within:
```
root@localhost:/sdcard# borg import-tar --list --info -r BX2 SolarisEAs_FIFO_SymLink Download/SolarisEAs_FIFO_SymLink.tar /usr/lib/python3/dist-packages/requests/__init__.py:87: RequestsDependencyWarning: urllib3 (1.26.5) or chardet (5.2.0) doesn't match a supported version! warnings.warn("urllib3 ({}) or chardet ({}) doesn't match a supported " /usr/lib/python3/dist-packages/trio/_core/_multierror.py:511: RuntimeWarning: You seem to already have a custom sys.excepthook handler installed. I'll skip installing Trio's custom handler, but this means MultiErrors will not show full tracebacks. warnings.warn( d SolarisMetadata s SolarisMetadata/rcm_daemon_door f SolarisMetadata/SolarisFIFO /dev/null/..hdr: Unsupported tarinfo type b'E' E /dev/null/..hdr /dev/null/.: Unsupported tarinfo type b'E' E /dev/null/. /dev/null/ANewAttribute.hdr: Unsupported tarinfo type b'E' E /dev/null/ANewAttribute.hdr /dev/null/ANewAttribute: Unsupported tarinfo type b'E' E /dev/null/ANewAttribute /dev/null/copy-SUNWattr_ro.hdr: Unsupported tarinfo type b'E'
E /dev/null/copy-SUNWattr_ro.hdr /dev/null/copy-SUNWattr_ro: Unsupported tarinfo type b'E'
E /dev/null/copy-SUNWattr_ro /dev/null/copy-SUNWattr_rw.hdr: Unsupported tarinfo type b'E' E /dev/null/copy-SUNWattr_rw.hdr /dev/null/copy-SUNWattr_rw: Unsupported tarinfo type b'E' E /dev/null/copy-SUNWattr_rw
```

I believe that Borg 2.0.0b12 is ostensibly supposed to support "SunOS tar with extended attributes" files, but I am unsure if this is supposed to extend to Solaris 10-originated archives.

The archives are available at https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/understand/SolarisEAs_FIFO_SymLink.tar, and https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/understand/SolarisEAs1.tar

#### Can you reproduce the problem? If so, describe how. If not, describe troubleshooting steps you took before opening the issue.

#### Include any warning/errors/backtraces from the system logs