sysutils/conky{-awesome}: update to 1.21.0

ChangeLog: https://github.com/brndnmtthws/conky/releases/tag/v1.21.0

Features

• Update DPI when changed in resource manager
• CLI: -V now displays a short version string
• Make version string semver compliant, add git sha
• Add BUILD_COLOUR_NAME_MAP build flag
• Docker: updated base image to Ubuntu 24.04 LTS
• Docker: improve tagging, distinguish main and latest
• Introduce geometry primitives

Bug fixes

• Fix bad query_x11_windows early returns
• Re-enable RSS in AppImage, also enable in Nix flake
• Disable -Wregister on gperf output
• Simplify binary include handling (and fix build)
• Require gperf at build-time
• Docker: Add gperf, enable Lua Cairo Xlib bindings
• Fix conky-cairo_imlib2_helper dependency conditions
• Use private mapping from provided shm_pool buffer
• Remove dpi scaling of maximum width
• Use _NET_VIRTUAL_ROOTS for querying virtual roots
• Use MODULE library type for Lua libs
• Fix AppImage version naming
• Ensure we use correct LLVM in nix dev shell
• Fix alignment documentation & enable HTML in docs

Miscellaneous

• Bump version
• Explicitly note updated time is UTC
• Link to latest commit in web footer
• Update nix flake w/ LLVM 18
• shared_ptr::unique() deprecated, use use_count()
• Bump minor version
• Fix this env var handling (derp)
• Try to fix this quote handling again
• Move docker build to separate script for less jank
• Docker build separate script