dependency: gcovr 3.4

[moderation]

dependency: Investigate updating to gcovr 3.4

Description: gcovr 3.4 was recently released (release notes). There are work arounds in the code for gcovr 3.3 bugs that are outlined at

envoy/ci/do_ci.sh

Lines 127 to 135 in 43df022

	# There is a bug in gcovr 3.3, where it takes the -r path,
	# in our case /source, and does a regex replacement of various
	# source file paths during HTML generation. It attempts to strip
	# out the prefix (e.g. /source), but because it doesn't do a match
	# and only strip at the start of the string, it removes /source from
	# the middle of the string, corrupting the path. The workaround is
	# to point -r in the gcovr invocation in run_envoy_bazel_coverage.sh at
	# some Bazel created symlinks to the source directory in its output
	# directory. Wow.

Question is should we investigate 3.4 or stay on 3.3 until gcovr is replaced which is covered in #1000

[mattklein123]

Realistically I'm not sure how soon coverage is really going to change. @moderation I would just do the upgrade if you feel like it. Thank you!

[htuch]

Bazel team are working on fixing coverage to support lcov atm, so there is reason to suspect we might get lcov in the medium term.

[keith]

FYI I'm updating gcovr to 3.4 in this PR #7391 (4.1 is out but it would require quite a few more changes) but I didn't revisit this comment, so that's something we could do after merging

[lizan]

We're no longer using gcovr.