fix: use deepin-pdfium in system default

[hillwoodroc]

use deepin-pdfium in system default

Log: deepin-pdfium was split as a single package, 3rdparty is no longer useful

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: hillwoodroc

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[deepin-bot]

TAG Bot

New tag: 6.0.8
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #95

[deepin-bot]

TAG Bot

New tag: 6.0.9
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #99

[BLumia]

REUSE 合规检查：

https://github.com/linuxdeepin/deepin-reader/actions/runs/9078693700?pr=86#summary-24946254044

应该是你移除3rdparty目录后，原本那里的BSD许可不再被需要了，删掉LICENSES/目录下的BSD-3-Clause对应的文件就行了

[deepin-bot]

TAG Bot

New tag: 6.0.10
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #102

[deepin-bot]

TAG Bot

New tag: 6.5.0
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #108

[deepin-bot]

TAG Bot

New tag: 6.5.1
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #113

[deepin-bot]

TAG Bot

New tag: 6.5.2
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #117

[deepin-bot]

TAG Bot

New tag: 6.5.3
DISTRIBUTION: unstable
Suggest: synchronizing this PR through rebase #122