chore(deps): bump gcovr from 8.3 to 8.4 in /.devcontainer (#950)

Bumps [gcovr](https://github.com/gcovr/gcovr) from 8.3 to 8.4.
- [Release notes](https://github.com/gcovr/gcovr/releases)
- [Changelog](https://github.com/gcovr/gcovr/blob/main/CHANGELOG.rst)
- [Commits](gcovr/gcovr@8.3...8.4)

---
updated-dependencies:
- dependency-name: gcovr
  dependency-version: '8.4'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.devcontainer/cpp/requirements.in

@@ -1,3 +1,3 @@
 cmake==4.1.0
 conan==2.20.1
-gcovr==8.3
+gcovr==8.4

.devcontainer/cpp/requirements.txt

@@ -155,9 +155,9 @@ fasteners==0.19 \
     --hash=sha256:758819cb5d94cdedf4e836988b74de396ceacb8e2794d21f82d131fd9ee77237 \
     --hash=sha256:b4f37c3ac52d8a445af3a66bce57b33b5e90b97c696b7b984f530cf8f0ded09c
     # via conan
-gcovr==8.3 \
-    --hash=sha256:d613a90aeea967b4972fbff69587bf8995ee3cd80df2556983b73141f30642d2 \
-    --hash=sha256:faa371f9c4a7f78c9800da655107d4f99f04b718d1c0d9f48cafdcbef0049079
+gcovr==8.4 \
+    --hash=sha256:1016d013d6c55225b1f716a4325e16ad5d626ff05b20b8a12d542e2d9a82ac21 \
+    --hash=sha256:8ea0cf23176b1029f28db679d712ca6477b3807097c3755c135bdc53b51cfa72
     # via -r cpp/requirements.in
 idna==3.10 \
     --hash=sha256:12f65c9b470abda6dc35cf8e63cc574b1c52b11df2c86030af0ac09b01b13ea9 \