Use new build image 0.20.3

[chaudum]

What this PR does / why we need it:

The new build image uses the latest version v1.45.2 of golangci-lint. With this version running the make lint locally yields the same results as running on CI.

Special notes for your reviewer:

• Requires Other: trigger build of loki-build-image:0.20.3 #5924 so that 0.20.3 is built
• This PR contains commits from Update golangci-lint in build image #5901
• The changes in file .drone/drone.yml were generated by make drone
• Code changes are fixes for the linter:

   pkg/storage/stores/tsdb/index/index.go:1525:61: unexported-return: exported func ReadFingerprintOffsetsTable returns unexported type index.fingerprintOffsets, which can be annoying to use (revive)
   func ReadFingerprintOffsetsTable(bs ByteSlice, off uint64) (fingerprintOffsets, error) {
                                                            ^
   pkg/ingester/ingester.go:554:59: unexported-return: exported method GetOrCreateInstance returns unexported type *ingester.instance, which can be annoying to use (revive)
   func (i *Ingester) GetOrCreateInstance(instanceID string) *instance {
  

[jeschkies]

Ok, according to the build **logs** of you build image change. It pushed grafana/loki-build-image:0.20.2

And I know why. You didn't regenerate the drone.yml 🙈 make check-drone-drift was supposed to catch that.

[jeschkies]

Since you recent change just overrode 0.20.2 it should be that

Suggested change

	BUILD_IMAGE_VERSION := 0.20.3
	BUILD_IMAGE_VERSION := 0.20.2

[chaudum]

0.20.2 was built but never been used, see 4353916#diff-60045f9474705196e786df20a7bb40d29e013e47a3b6927153a10b9acac82266L358

[jeschkies]

This change seems unrelated.

[chaudum]

The new linter version reports: unexported-return: exported method GetOrCreateInstance returns unexported type *ingester.instance