I just migrate the server with odoo version from 13e to 15e

2022-03-09 13:06:17,859 8443 WARNING ? py.warnings: /usr/lib/python3/dist-packages/reportlab/lib/utils.py:7: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses

Also when we check front end it will shows Style Error as below:

The style compilation failed, see the error below. Your recent actions may be the cause, please try reverting the changes you made.
/usr/local/lib/python3.6/dist-packages/sassc.py:9: FutureWarning: The `sassc` entrypoint is deprecated, please use `pysassc`
  FutureWarning,
Usage: sassc [options] SCSS_FILE [OUT_CSS_FILE]
sassc: error: no such option: --stdin
This error occurred while compiling the bundle 'web.assets_common' containing:
    - /web/static/lib/bootstrap/scss/_functions.scss
    - /web/static/lib/bootstrap/scss/_mixins.scss
    - /web/static/src/legacy/scss/bs_mixins_overrides.scss
    - /web/static/src/legacy/scss/utils.scss
    - /web_enterprise/static/src/legacy/scss/primary_variables.scss
    - /web/static/src/legacy/scss/primary_variables.scss
    - /web_editor/static/src/scss/web_editor.variables.scss
    - /web/static/src/legacy/scss/secondary_variables.scss
    - /web_editor/static/src/scss/secondary_variables.scss
    - /web_enterprise/static/src/legacy/scss/secondary_variables.scss
    - /web/static/lib/bootstrap/scss/_variables.scss
    - /web/static/src/legacy/scss/tempusdominus_overridden.scss
    - /web/static/lib/tempusdominus/tempusdominus.scss
    - /web/static/fonts/fonts.scss
    - /web/static/src/legacy/scss/ui.scss
    - /web_enterprise/static/src/legacy/scss/ui.scss
    - /web/static/src/legacy/scss/navbar.scss
    - /web/static/src/legacy/scss/mimetypes.scss
    - /web/static/src/legacy/scss/modal.scss
    - /web/static/src/legacy/scss/animation.scss
    - /web/static/src/legacy/scss/datepicker.scss
    - /web/static/src/legacy/scss/daterangepicker.scss
    - /web/static/src/legacy/scss/banner.scss
    - /web/static/src/legacy/scss/colorpicker.scss
    - /web/static/src/legacy/scss/popover.scss
    - /web/static/src/legacy/scss/translation_dialog.scss
    - /web/static/src/legacy/scss/keyboard.scss
    - /web/static/src/legacy/scss/name_and_signature.scss
    - /web/static/src/legacy/scss/web.zoomodoo.scss
    - /web/static/src/legacy/scss/color_picker.scss
    - /web/static/src/legacy/scss/fontawesome_overridden.scss
    - /web_enterprise/static/fonts/fonts.scss
    - /web_tour/static/src/scss/tip.scss