upgrade bootstrap 5.3.0

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (ed59d2a) 100.00% compared to head (e47e691) 100.00%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #301 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 1 1 Lines 136 136 Branches 16 16 ========================================= Hits 136 136 ``` | [Impacted Files](https://app.codecov.io/gh/helloflask/bootstrap-flask/pull/301?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=helloflask) | Coverage Δ | | |---|---|---| | [flask\_bootstrap/\_\_init\_\_.py](https://app.codecov.io/gh/helloflask/bootstrap-flask/pull/301?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=helloflask#diff-Zmxhc2tfYm9vdHN0cmFwL19faW5pdF9fLnB5) | `100.00% <100.00%> (ø)` | |

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[PanderMusubi]

The default CDN version and integrity values should be updated as well. https://github.com/helloflask/bootstrap-flask/blob/master/flask_bootstrap/__init__.py#L262-L266

Thanks. Will do later today.

[PanderMusubi]

Done, also updated https://github.com/helloflask/bootstrap-flask/discussions/300

[PanderMusubi]

@greyli I see there is also an upgrade of popper from 2.11.6 to 2.11.8. Add that also to this PR?

[PanderMusubi]

@greyli I also see Bootswatch is at 5.3.0 now. I will upgrade that and popper this week and hope we can release soon after that if is okay with you?

[greyli]

I also see Bootswatch is at 5.3.0 now. I will upgrade that and popper this week and hope we can release soon after that if is okay with you?

LGTM.

[greyli]

Merged. I will upgrade Popper and then release 2.3.0.