Suppress clang warnings

Some trivial changes to suppress some clang warnings recently introduced in master

../Event/RecEvent/include/Event/PrimaryVertices.h:193:29: warning: explicitly defaulted copy assignment operator is implicitly deleted [-Wdefaulted-function-deleted]
../Event/TrackEvent/include/Event/PrVeloTracks.h:55:3: warning: 'Tracks' defined as a struct here but previously declared as a class; this is valid, but may result in linker errors under the Microsoft C++ ABI [-Wmismatched-tags]

added 1 commit

• 2eb7a106 - PrimaryVertices.h: Suppress some trivial clang warnings

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added RTA label

/ci-test

added ci-test-triggered label

• [2022-04-11 12:45] Validation started with lhcb-master-mr#4209

added 3 commits

• 2eb7a106...58e01d88 - 2 commits from branch lhcb:master
• 0883fce8 - PrimaryVertices.h: Suppress some trivial clang warnings

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resolved all threads

merged

mentioned in commit c33a4c35

added cleanup label

mentioned in issue Moore#421 (closed)