When generating a changelog without an explicit start commit, we try to
find the tag of the previous release. Prior to this commit, the regex
used for this was fixed. This creates a problem for projects that use a
different tag format, including our very own Omnibus project. Omnibus
uses RC tags in the following format:

    13.10.0+rc41.ee.0

According to semantic versioning, this isn't a pre-release tag. Instead,
the `rc412.ee.0` suffix is part of the build metadata.

Changing Omnibus to use a correct tag format would be time consuming,
and delay rolling out the use of the new changelog API for our own
projects. In addition, other projects could suffer from similar problems
where a tag perhaps includes a valid version, but our fixed regex
doesn't match it.

In this commit we fix this by adding support for custom regular
expressions to extract versions from tag names. We use the re2 engine
for this instead of Ruby's regex engine, based on the issues with this
as outlined in our documentation [1]. Using a re2 pattern, we try to
extract the major, minor, patch, and build metadata components. We still
skip tags that produce a prerelease component. If a tag doesn't produce
at least the major, minor and patch components, it's ignored.

The default pattern we use is based on the official semver regex, with
added support of tags starting with the letter "v" (to keep the change
backwards compatible). Users wishing to use a custom format can probably
use a much simpler pattern, as they only need to support their own use
formats. For example, for Omnibus we could simply use something along
the lines of the following pattern (minus newlines):

    ^
    (?P<major>\d+)
    \.(?P<minor>\d+)
    \.(?P<patch>\d+)
    (\+(?P<prerelease>rc\d+))?
    (\.(?P<buildmetadata>\w+\.\d+))?
    $

See https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/1551 for
more information.

[1]: https://docs.gitlab.com/ee/development/secure_coding_guidelines.html#regular-expressions-guidelines

Resolve "Index namespaces.traversal_ids"

See merge request gitlab-org/gitlab!57207

Add GIT_COMMIT_AUTHOR predefined variable

See merge request gitlab-org/gitlab!56144

Signed-off-by: Craig Andrews <candrews@integralblue.com>

Convert Commit dropdown to Vue

See merge request gitlab-org/gitlab!56142

- follow pajamas design pattern.

Improve gitlab_ci_queue_size_total metric

See merge request gitlab-org/gitlab!57143

Set the scope in search context from group issue and MR pages

See merge request gitlab-org/gitlab!56383

Ignore peek-related backtrace lines

See merge request gitlab-org/gitlab!57208

Add descriptions to PipelineConfigSourceEnum

See merge request gitlab-org/gitlab!57003

Resolve rubocop offense Migration/DepartmentName

See merge request gitlab-org/gitlab!56997

Use a single query to compute excess storage

See merge request gitlab-org/gitlab!57088

Lower the frequency of which job trace updates occur [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!56743

Remove unnecessary use of freeze

See merge request gitlab-org/gitlab!57058

Remove unnecessary use of freeze

See merge request gitlab-org/gitlab!57056

Remove unnecessary use of freeze

See merge request gitlab-org/gitlab!57060

Remove unnecessary use of freeze

See merge request gitlab-org/gitlab!57057

Removed some unused at extends from SCSS

See merge request gitlab-org/gitlab!57012

The chained and :focus ones had no impact, other than adding margin
bottom to card-body when it is also a card, which is odd.
The description-block appears to be unused (file not in startupcss)

Revert move-recursive-ns-query-to-inner-join [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!57131

Add missing gitlab_service_measuring_projects_ feature flag definition files [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!57215

Add missing x509_forced_cert_loading ff definition file [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!57217

Split and rename project issue sidebar specs

See merge request gitlab-org/gitlab!56818

Revert HTTP connection adapter with proxy settings

See merge request gitlab-org/gitlab!57152

Reposition epics on the board using graphQL

See merge request gitlab-org/gitlab!56236

Fixed an issue where the link commit message did not end with a newline

See merge request gitlab-org/gitlab!49086

Fix specs when load balanicng is configured

See merge request gitlab-org/gitlab!57107

Fix Workhorse acceleration for encoded project IDs in API

See merge request gitlab-org/gitlab!56731

This reverts commit ee1e606f, reversing
changes made to 6f95667d.

Change Migrations.md to OSS_Partner.md

See merge request gitlab-org/gitlab!57132

Add dropdown and feature flag [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!56865

Add dropdown, unstyled

Adds new component, constants

Add code style for needs

Add specs for dropdown, translations

Add a global feature flag for tracking using Redis HLL [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!56970

Create Apollo Link for Captcha handling

See merge request gitlab-org/gitlab!56879

Resolve "timezones don't encode special characters properly"

See merge request gitlab-org/gitlab!56792