feat: Release version 5.6.0

Summary of changes since 5.5.0:
- Generate static bindgens for ICU 78 with buildenv 1.91.0.
- Update buildenv to 1.91.0 to support ICU 78.
- Patch lib_78 and lib_79 with correct version numbers.
- Update release process documentation in GEMINI.md.
- General maintenance and coverage report updates.

This commit was created by an automated coding assistant, with human
supervision.

feat: Release version 5.5.0

Summary of changes since 5.4.0:
- fix: add missing Dutch pluralization and spellout formats
- test: convert failing Serbian tests to Dutch
- fix: add bindgen for ICU 78 and (upcoming) 79
- feat: update the docker buildenv
- fix: update bindgens
- fix: expire ICU versions older than 74
- Update ICU version compatibility table in README

This commit was created by an automated coding assistant, with human supervision.

feat: add support for ICU 78 to buildenv

This commit was created by an automated coding assistant, with human
supervision.

feat: Release version 5.4.0

This release updates the version of all crates to 5.4.0.

Changes since 5.0.0:
- fix(Makefile): move building of rust_icu_uloc to a make dependency
- fix(rust_icu_release): remove use of `unwrap` for more sensible error reporting
- fix(rust_icu_udat): specify the release crate version in Cargo.toml
- fix: forward the PKG_CONFIG_PATH to cargo
- Add license to `rust_icu_release`
- fix: crates.io publication requires metadata
- feat: Release version 5.3.0
- fix: handle some bitrot items
- feat: release version 5.2.0
- feat: release version 5.1.0
- Fix: Correct release version files
- chore: update version files for next release cycle
- feat: release version 5.1.0
- Add bindings for ICU 77.
- feat: add the procedures for robotic code changes
- clean: move versions into top-level files
- doc: update the version support matrix
- clean: limits the parallelism of builds
- chore: release a new buildenv (1.82.0) and a new ToT builder
- feat: create a container for building ICU against `main`
- fix: the config file extension is not required to be .toml

This commit was created by an automated coding assistant, with human
supervision.

feat: Release version 5.3.0

This commit was created by an automated coding assistant, with human
supervision.

feat: release version 5.2.0

This release includes the following changes:
- Bindings for ICU 77.
- Robotic code change procedures.
- Version files moved to top-level.
- Updated version support matrix.
- Limited parallelism of builds.
- New buildenv (1.82.0) and ToT builder.
- Container for building ICU against `main`.
- Fix for config file extension.

This commit was created by an automated coding assistant, with human
supervision.

feat: release version 5.1.0

This release includes the following changes:
- Add bindings for ICU 77.
- Add procedures for robotic code changes.
- Update the version support matrix.
- Limit the parallelism of builds.
- Create a container for building ICU against `main`.
- Fix the config file extension.

This commit was created by an automated coding assistant, with human
supervision.

Merge branch 'filmil-mascot'

chore: update the release to 4.2.3

Fix a scoping bug.

Issue: #282

feat: support UDataMemory::open

This should be a better way to manage the resource
memory, as resources created by `open` are memory
mapped on demand.

Some memory-constrained execution environments may
care.