Update module prometheus/client_golang to v1.9.0

This MR contains the following updates:

Package	Type	Update	Change
github.com/prometheus/client_golang	require	minor	v1.5.1 -> v1.9.0

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Release Notes

prometheus/client_golang

v1.9.0

Compare Source

• [FEATURE] NewPidFileFn helper to create process collectors for processes whose PID is read from a file. #​804
• [BUGFIX] promhttp: Prevent endless loop in InstrumentHandler... middlewares with invalid metric or label names. #​823

v1.8.0

Compare Source

• [CHANGE] API client: Use time.Time rather than string for timestamps in RuntimeinfoResult. #​777
• [FEATURE] Export MetricVec to facilitate implementation of vectors of custom Metric types. #​803
• [FEATURE API client: Support /status/tsdb endpoint. #​773
• [ENHANCEMENT] API client: Enable GET fallback on status code 501. #​802
• [ENHANCEMENT] Remove Metric references after reslicing to free up more memory. #​784

v1.7.1

Compare Source

• [BUGFIX] API client: Actually propagate start/end parameters of LabelNames and LabelValues. #​771

v1.7.0

Compare Source

• [CHANGE] API client: Add start/end parameters to LabelNames and LabelValues. #​767
• [FEATURE] testutil: Add GatherAndCount and enable filtering in CollectAndCount #​753
• [FEATURE] API client: Add support for status and runtimeinfo endpoints. #​755
• [ENHANCEMENT] Wrapping nil with a WrapRegistererWith... function creates a no-op Registerer. #​764
• [ENHANCEMENT] promlint: Allow Kelvin as a base unit for cases like color temperature. #​761
• [BUGFIX] push: Properly handle empty job and label values. #​752

v1.6.0

Compare Source

• [FEATURE] testutil: Add lint checks for metrics, including a sub-package promlint to expose the linter engine for external usage. #​739 #​743
• [ENHANCEMENT] API client: Improve error messages. #​731
• [BUGFIX] process collector: Fix process_resident_memory_bytes on 32bit MS Windows. #​734

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go.mod

@@ -16,7 +16,7 @@ require (
 	github.com/lunixbochs/struc v0.0.0-20200707160740-784aaebc1d40
 	github.com/miscreant/miscreant.go v0.0.0-20200214223636-26d376326b75
 	github.com/openzipkin/zipkin-go v0.2.2
-	github.com/prometheus/client_golang v1.5.1
+	github.com/prometheus/client_golang v1.9.0
 	github.com/russross/blackfriday/v2 v2.0.1
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
 	github.com/theckman/go-flock v0.7.1