Twenty Fifteen: Calendar block font size does not change with block setting

[pranitdugad]

In Twenty fifteen, The Calendar block Typography option is not working properly. if we compare it with other themes when we change the typography size the whole content of the calendar changes but here only the bottom months change.
Here is the Video for proper understanding :
​https://drive.google.com/file/d/1IpXUCDk5NY6H9b_SsO5c6y38RbiZTvCu/view?usp=sharing

[pranitdugad]

After applying this patch , this issue is resolved

[viralsampat]

I have checked the above-mentioned issue and its patch and found that we need to change the "table header" font size too. Here, I have added new patch.

[darshitrajyaguru97]

Test Report

Patch tested: https://core.trac.wordpress.org/attachment/ticket/59989/59989.2.patch

Environment:

OS: Windows
PHP: 8.2.12
WordPress: 6.5
Browser: Chrome
Theme: Twenty Fifteen
Plugins: None activated

Actual Results:

✅ Before patch:
Backend: ​https://prnt.sc/37NswqjPuXQI
Frontend: ​https://prnt.sc/SLfDeuZsP_VF

✅ After patch:
Backend: ​https://prnt.sc/b_r6Y6-pb-al
Frontend: ​https://prnt.sc/YItd3A8GTUXa

✅ Patch working well as desired solution

[sabernhardt]

I prefer the changes in 59989.2.patch instead of adding more styles for the Table and Calendar blocks, so I will build off of that for the patch on #59602.