Modernize Python type hints and string formatting

[cclauss]

Description

Please include a summary of the change and which issue is fixed. Please also
include relevant motivation and context. Your commit message should include
this information as well.

Fixes # (issue)

Checklist:

• I have added the relevant tests for this change.
• I have added an item to the Pending section of docs/changes.rst.

Fixed 19 errors:

• debug_toolbar/utils.py:
  11 × UP006 (non-pep585-annotation)
  5 × UP007 (non-pep604-annotation)
• tests/test_csp_rendering.py:
  3 × UP006 (non-pep585-annotation)

Fixed 25 errors:

• debug_toolbar/panels/profiling.py:
  1 × UP031 (printf-string-formatting)
  1 × UP032 (f-string)
• debug_toolbar/panels/sql/forms.py:
  1 × UP031 (printf-string-formatting)
  1 × UP032 (f-string)
• debug_toolbar/panels/versions.py:
  1 × UP031 (printf-string-formatting)
  1 × UP032 (f-string)
• debug_toolbar/toolbar.py:
  1 × UP031 (printf-string-formatting)
• debug_toolbar/views.py:
  1 × UP031 (printf-string-formatting)
  1 × UP032 (f-string)
• tests/base.py:
  2 × UP031 (printf-string-formatting)
  2 × UP032 (f-string)
• tests/test_csp_rendering.py:
  2 × UP031 (printf-string-formatting)
  2 × UP032 (f-string)
• tests/test_integration.py:
  2 × UP031 (printf-string-formatting)
  2 × UP032 (f-string)
• tests/test_integration_async.py:
  2 × UP031 (printf-string-formatting)
  2 × UP032 (f-string)

[matthiask]

Thanks!