[Common] Reduce verbosity of ctpRateFetcher when trigger classes are not found

[fchinu]

In part of 2023 the trigger name changed, so the CMTVX-B-NOPF trigger class for some periods is not found. Both the "Trying different class" and the "class not found" message were logged at info/warn level, and since fetch() is called per collision in the TPC PID service task

O2Physics/Common/Tools/PID/pidTPCModule.h

Line 523 in ede5910

hadronicRateForCollision[i] = mRateFetcher.fetch(ccdb.service, bc.timestamp(), bc.runNumber(), irSource) * 1.e-3;

this produced very large log files, causing jobs to fail because of Too much disk space used: https://alimonitor.cern.ch/agent/jobs/details.jsp?pid=3677551603
This PR demotes both messages to LOG(debug)

[github-actions]

O2 linter results: ❌ 4 errors, ⚠️ 1 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 0e07c32 at 2026-08-07 21:26:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 5 errors and 0 warnings.'
Found 5 errors and 0 warnings.
++ [[ 5 -gt 0 ]]
++ cat /sw/BUILD/ca6b292b049264555843989e8db0da9170d76e54/O2Physics-code-check/errors.txt
Common/CCDB/ctpRateFetcher.cxx:37:7: error: do not use 'else' after 'return' [readability-else-after-return,-warnings-as-errors]
Common/CCDB/ctpRateFetcher.cxx:47:7: error: do not use 'else' after 'return' [readability-else-after-return,-warnings-as-errors]
Common/CCDB/ctpRateFetcher.cxx:78:79: error: implicit conversion 'int' -> 'bool' [readability-implicit-bool-conversion,-warnings-as-errors]
Common/CCDB/ctpRateFetcher.cxx:86:82: error: implicit conversion 'int' -> 'bool' [readability-implicit-bool-conversion,-warnings-as-errors]
Common/CCDB/ctpRateFetcher.cxx:87:5: error: do not use 'else' after 'return' [readability-else-after-return,-warnings-as-errors]
++ [[ 0 -gt 0 ]]
++ [[ 5 -gt 0 ]]
++ exit 1
--

Full log here.