fix(deps): update renovate/renovate docker tag

This MR contains the following updates:

Package	Update	Change
renovate/renovate	patch	29.12.4 -> 29.12.8
renovate/renovate	patch	29.12.4-slim -> 29.12.7-slim

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Release Notes

renovatebot/renovate

v29.12.8

29.12.8 (2021-11-18)

Bug Fixes

• git-refs: ignore refs/for (#​12735) (e095d5a)

v29.12.7

29.12.7 (2021-11-18)

Bug Fixes

• git: catch matches more than one (e0c1d31), closes #​12734

v29.12.6

29.12.6 (2021-11-18)

Bug Fixes

• config/preset: readd subpreset support (#​12733) (baaea71)

v29.12.5

29.12.5 (2021-11-18)

Bug Fixes

• cache handle nested err (#​12730) (d3eb6fe)

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